LC-MS/MS-based multibiomarker approaches for the assessment of human exposure to mycotoxins

High-Coverage UHPLC-MS/MS Analysis of 67 Mycotoxins in Plasma for Male Infertility Exposure Studies

Mycotoxins are a class of exogenous metabolites that are major contributors to foodborne diseases and pose a potential threat to human health. However, little attention has been paid to trace mycotoxin co-exposure situations in vivo. To address this, we devised a novel analytical strategy, both highly sensitive and comprehensive, for quantifying 67 mycotoxins in human plasma samples. This method employs isotope dilution mass spectrometry (IDMS) for approximately 40% of the analytes and utilizes internal standard quantification for the rest. The mycotoxins were classified into three categories according to their physicochemical properties, facilitating the optimization of extraction and detection parameters to improve analytical performance. The lowest limits of detection and quantitation were 0.001-0.5 μg/L and 0.002-1 μg/L, respectively, the intra-day precision ranged from 1.8% to 11.9% RSD, and the intra-day trueness ranged from 82.7-116.6% for all mycotoxins except Ecl, DH-LYS, PCA, and EnA (66.4-129.8%), showing good analytical performance of the method for biomonitoring. A total of 40 mycotoxins (including 24 emerging mycotoxins) were detected in 184 plasma samples (89 from infertile males and 95 from healthy males) using the proposed method, emphasizing the widespread exposure of humans to both traditional and emerging mycotoxins. The most frequently detected mycotoxins were ochratoxin A, ochratoxin B, enniatin B, and citrinin. The incidence of exposure to multiple mycotoxins was significantly higher in infertile males than in healthy subjects, particularly levels of ochratoxin A, ochratoxin B, and citrinin, which were significantly increased. It is necessary to carry out more extensive biological monitoring to provide data support for further study of the relationship between mycotoxins and male infertility.

Assessing human exposure to pesticides and mycotoxins: optimization and validation of a method for multianalyte determination in urine samples

Humans are exposed to an increasing number of contaminants, with diet being one of the most important exposure routes. In this framework, human biomonitoring is considered the gold standard for evaluating human exposure to chemicals. Pesticides and mycotoxins are chemicals of special concern due to their health implications. They constitute the predominant border rejection notifications for food and feed in Europe and the USA. However, current biomonitoring studies are focused on a limited number of compounds and do not evaluate mycotoxins and pesticides together. In this study, an analytical method has been developed for the determination of 30 pesticides and 23 mycotoxins of concern in urine samples. A salting-out liquid-liquid extraction (SALLE) procedure was optimized achieving recoveries between 70 and 120% for almost all the compounds and limits as lower as when QuEChERS was applied. The compounds were then determined by liquid chromatography coupled to triple quadrupole mass spectrometry. Different chromatographic conditions and analytical columns were tested, selecting a Hypersild gold aQ column as the best option. Finally, the method was applied to the analysis of 45 urine samples, in which organophosphate and pyrethroid pesticides (detection rates (DR) of 82% and 42%, respectively) and ochratoxin A and deoxynivalenol (DR of 51% and 33%, respectively) were the most detected compounds. The proposed analytical method involves the simultaneous determination of a diverse set of pesticides and mycotoxins, including their most relevant metabolites, in human urine. It serves as an essential tool for biomonitoring the presence of highly prevalent contaminants in modern society.

Literature review and evaluation of biomarkers, matrices and analytical methods for chemicals selected in the research program Human Biomonitoring for the European Union (HBM4EU)

Humans are potentially exposed to a large amount of chemicals present in the environment and in the workplace. In the European Human Biomonitoring initiative (Human Biomonitoring for the European Union = HBM4EU), acrylamide, mycotoxins (aflatoxin B1, deoxynivalenol, fumonisin B1), diisocyanates (4,4'-methylenediphenyl diisocyanate, 2,4- and 2,6-toluene diisocyanate), and pyrethroids were included among the prioritized chemicals of concern for human health. For the present literature review, the analytical methods used in worldwide biomonitoring studies for these compounds were collected and presented in comprehensive tables, including the following parameter: determined biomarker, matrix, sample amount, work-up procedure, available laboratory quality assurance and quality assessment information, analytical techniques, and limit of detection. Based on the data presented in these tables, the most suitable methods were recommended. According to the paradigm of biomonitoring, the information about two different biomarkers of exposure was evaluated: a) internal dose = parent compounds and metabolites in urine and blood; and b) the biologically effective = dose measured as blood protein adducts. Urine was the preferred matrix used for deoxynivalenol, fumonisin B1, and pyrethroids (biomarkers of internal dose). Markers of the biological effective dose were determined as hemoglobin adducts for diisocyanates and acrylamide, and as serum-albumin-adducts of aflatoxin B1 and diisocyanates. The analyses and quantitation of the protein adducts in blood or the metabolites in urine were mostly performed with LC-MS/MS or GC-MS in the presence of isotope-labeled internal standards. This review also addresses the critical aspects of the application, use and selection of biomarkers. For future biomonitoring studies, a more comprehensive approach is discussed to broaden the selection of compounds.

High-Throughput Determination of Major Mycotoxins with Human Health Concerns in Urine by LC-Q TOF MS and Its Application to an Exposure Study

Human biomonitoring constitutes a suitable tool to assess exposure to toxins overcoming the disadvantages of traditional methods. Urine constitutes an accessible biological matrix in biomonitoring studies. Mycotoxins are secondary metabolites produced naturally by filamentous fungi that produce a wide range of adverse health effects. Thus, the determination of urinary mycotoxin levels is a useful tool for assessing the individual exposure to these food contaminants. In this study, a suitable methodology has been developed to evaluate the presence of aflatoxin B2 (AFB2), aflatoxin (AFG2), ochratoxin A (OTA), ochratoxin B (OTB), zearalenone (ZEA), and α-zearalenol (α-ZOL) in urine samples as exposure biomarkers. For this purpose, different extraction procedures, namely, the Solid Phase Extraction (SPE); Dispersive Liquid–Liquid Microextraction (DLLME); and Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) methods were assessed, followed by Liquid Chromatography coupled to Quadrupole Time of Flight Mass Spectrometry with Electrospray Ionization (LC-ESI-QTOF-MS) determination. Then, the proposed methodology was applied to determine mycotoxin concentrations in 56 human urine samples from volunteers and to estimate the potential risk of exposure. The results obtained revealed that 55% of human urine samples analyzed resulted positive for at least one mycotoxin. Among all studied mycotoxins, only AFB2, AFG2, and OTB were detected with incidences of 32, 41, and 9%, respectively, and levels in the range from <LOQ to 69.42 µg/L. Risk assessment revealed a potential health risk, obtaining MoE values < 10,000. However, it should be highlighted that few samples were contaminated, and that more data about mycotoxin excretion rates and their BMDL10 values are needed for a more accurate risk assessment.

Mycotoxin exposure biomonitoring in breastfed and non-exclusively breastfed Nigerian children

A multi-specimen, multi-mycotoxin approach involving ultra-sensitive LC-MS/MS analysis of breast milk, complementary food and urine was applied to examine mycotoxin co-exposure in 65 infants, aged 1-18 months, in Ogun state, Nigeria. Aflatoxin M₁ was detected in breast milk (4/22 (18%)), while six other classes of mycotoxins were quantified; including dihydrocitrinone (6/22 (27%); range: 14.0-59.7 ng/L) and sterigmatocystin (1/22 (5%); 1.2 ng/L) detected for the first time. Seven distinct classes of mycotoxins including aflatoxins (9/42 (21%); range: 1.0-16.2 µg/kg) and fumonisins (12/42 (29%); range: 7.9-194 µg/kg) contaminated complementary food. Mycotoxins covering seven distinct classes with diverse structures and modes of action were detected in 64/65 (99%) of the urine samples, demonstrating ubiquitous exposure. Two aflatoxin metabolites (AFM₁ and AFQ₁) and FB₁ were detected in 6/65 (9%), 44/65 (68%) and 17/65 (26%) of urine samples, respectively. Mixtures of mycotoxin classes were common, including 22/22 (100%), 14/42 (33%) and 56/65 (86%) samples having 2-6, 2-4, or 2-6 mycotoxins present, for breast milk, complementary food and urine, respectively. Aflatoxin and/or fumonisin was detected in 4/22 (18%), 12/42 (29%) and 46/65 (71%) for breast milk, complimentary foods and urine, respectively. Furthermore, the detection frequency, median concentrations and occurrence of mixtures were typically greater in urine of non-exclusively breastfed compared to exclusively breastfed infants. The study provides novel insights into mycotoxin co-exposures in early-life. Albeit a small sample set, it highlights transition to higher levels of infant mycotoxin exposure as complementary foods are introduced, providing impetus to mitigate during this critical early-life period and encourage breastfeeding.

A Novel Colorimetric Nano Aptasensor for Ultrasensitive Detection of Aflatoxin B1 Based on the Exonuclease III-Assisted Signal Amplification Approach

The detection of aflatoxin B1 (AFB1) has recently garnered much attention on the issue of food safety. In this study, a novel and sensitive aptasensor towards AFB1 is proposed using an Exonuclease III (Exo III)-integrated signal amplification strategy. This reported sensing strategy is regulated by aptamer-functionalized nanobeads that can target AFB1; furthermore, complementary DNA (cDNA) strands can lock the immobilized aptamer strands, preventing the signal amplification function of Exo III in the absence of AFB1. The presence of AFB1 triggers the displacement of cDNA, which will then activate the Exo III-integrated signal amplification procedure, resulting in the generation of a guanine (G)-rich sequence to form a G-4/hemin DNAzyme, which can catalyze the substrate of ABTS to produce a green color. Using this method, a practical detection limit of 0.0032 ng/mL and a dynamic range of detection from 0.0032 to 50 ng/mL were obtained. Additionally, the practical application of the established sensing method for AFB1 in complex matrices was demonstrated through recovery experiments. The recovery rate and relative standard deviations (RSD) in three kinds of cereal samples ranged from 93.83% to 111.58%, and 0.82% to 7.20%, respectively, which were comparable with or better than previously reported methods.

Mycotoxin Biomarkers in Pigs-Current State of Knowledge and Analytics

Farm animals are frequently exposed to mycotoxins, which have many adverse effects on their health and become a significant food safety issue. Pigs are highly exposed and particularly susceptible to mycotoxins, which can cause many adverse effects. For the above reasons, an appropriate diagnostic tool is needed to monitor pig' exposure to mycotoxins. The most popular tool is feed analysis, which has some disadvantages, e.g., it does not include individual exposure. In recent years, the determination of biomarkers as a method to assess the exposure to mycotoxins by using concentrations of the parent compounds and/or metabolites in biological matrices is becoming more and more popular. This review provides a comprehensive overview of reported in vivo mycotoxin absorption, distribution, metabolism and excretion (ADME) and toxicokinetic studies on pigs. Biomarkers of exposure for aflatoxins, deoxynivalenol, ochratoxin A, fumonisins, T-2 toxin and zearalenone are described to select the most promising compound for analysis of porcine plasma, urine and faeces. Biomarkers occur in biological matrices at trace levels, so a very sensitive technique-tandem mass spectrometry-is commonly used for multiple biomarkers quantification. However, the sample preparation for multi-mycotoxin methods remains a challenge. Therefore, a summary of different biological samples preparation strategies is included in that paper.

Alternaria toxins-Still emerging?

Alternaria molds are known to cause the contamination of food with their secondary metabolites, a chemically very heterogeneous group of compounds. Yet, after decades of research on the occurrence and the toxicity of Alternaria toxins in academia, no regulation has been implemented yet, thus leaving these potential food contaminants in the status of so-called "emerging mycotoxins". However, research on this topic has been far from static, leading to the European Food Safety Authority repeatedly calling for more data on the occurrence and toxicity of genotoxic metabolites such as alternariol (AOH) and its monomethyl ether (AME). To give an overview on recent developments in the field, this comprehensive review summarizes published data and addresses current challenges arising from the chemical complexity of Alternaria's metabolome, mixture effects and the emergence of novel biological targets like cell membranes or the interaction with different receptors. Besides toxicodynamics, we review recent research on toxicokinetics, including the first in vivo studies which incorporated the rarely investigated-but highly genotoxic-perylene quinones. Furthermore, a particular focus lies on the advances of liquid chromatography/tandem mass spectrometry (LC-MS/MS)-based analytical tools for determining a broader spectrum of Alternaria toxins including modified/masked forms and assessing exposure via human biomonitoring (HBM).

Assessment of Human Exposure to Deoxynivalenol, Ochratoxin A, Zearalenone and Their Metabolites Biomarker in Urine Samples Using LC-ESI-qTOF

Human are exposed to a wide range of mycotoxins through dietary food intake, including processed food. Even most of the mycotoxin exposure assessment studies are based on analysis of foodstuffs, and evaluation of dietary intake through food consumption patterns and human biomonitoring methods are rising as a reliable alternative to approach the individual exposures, overcoming the limitations of the indirect dietary assessment. In this study, human urine samples were analyzed, seeking the presence of deoxynivalenol (DON), ochratoxin A (OTA), zearalenone (ZEA), and their metabolites. For this purpose, 40 urine samples from female and male adult residents in the city of Valencia (Spain) were evaluated by liquid chromatography quadrupole time-of-flight mass spectrometry (LC-ESI-qTOF) after salting-out liquid–liquid extraction. Analytical data showed that 72.5% of analyzed samples were contaminated by at least one mycotoxin at variable levels. The most prevalent mycotoxins were de-epoxy DON (DOM-1) (53%), ZEA (40%), and α-zearalenol (αZOL) (43%), while OTA was only detected in one sample. The mean concentrations in positive samples were DON (9.07 ng/mL), DOM-1 (20.28 ng/mL), ZEA (6.70 ng/mL), ZEA-14 glucoside (ZEA-14-Glc) (12.43 ng/mL), αZOL (27.44 ng/mL), αZOL-14 glucoside (αZOL-14-Glc) (12.84 ng/mL), and OTA (11.73 ng/mL). Finally, probable daily intakes (PDIs) were calculated and compared with the established tolerable daily intakes (TDIs) to estimate the potential risk of exposure to the studied mycotoxins. The calculated PDI was below the TDI value established for DON in both female and male adults, reaching a percentage up to 30%; however, this percentage increased up to 92% considering total DON (DON + DOM-1). On the other hand, the PDI obtained for ZEA and its metabolites were higher than the TDI value fixed, but the low urine excretion rate (10%) considered should be highlighted. Finally, the PDI calculated in the detected positive sample for OTA exceeded the TDI value. The findings of the present study confirm the presence of the studied mycotoxins and their metabolites as some of the most prevalent in urine.

Development of an Analytical Method for Quantitation of Deoxynivalenol by UPLC-MS-MS: A Preliminary Assessment of Gestational and Lactational Transfer in Rats

Deoxynivalenol (DON) is the most widely distributed trichothecene mycotoxin in grain-based foods and animal feed. Exposure to DON is widespread as it has been detected in food sources from around the world. The objective of this work was to develop a method to quantitate DON in biological matrices and apply it in a preliminary assessment of gestational and lactational transfer of DON following exposure of pregnant rats. The method used protein precipitation followed by ultra-performance liquid chromatography-tandem mass spectrometry. The method was evaluated in male Sprague Dawley rat plasma over the concentration range ∼2-1,000 ng/mL. The method was linear (r ≥ 0.99), accurate (mean relative error ≤ ±4.9%) and precise (relative standard deviation ≤ 5.5%). The mean absolute recovery was 85.9%. The limit of detection was 0.35 ng/mL. The method was also evaluated in gestational day (GD) 18 Hsd:Sprague Dawley®SD® dam plasma and fetal homogenate (mean % relative error ≤ ±16.9; % relative standard deviation ≤ 9.5). Concentrations of DON in dam plasma stored at -80°C for at least 29 days and in fetal homogenate for at least 43 days were within 97.9 to 120% of Day 0 concentrations, demonstrating that DON is stable in these matrices. The method was used to quantitate DON in rat maternal plasma, amniotic fluid, GD 18 fetuses and postnatal day (PND) 4 pups following exposure of dams to 0 (control) and 1 mg/kg DON beginning on GD 6 and continuing through gestation and lactation for a preliminary assessment of maternal transfer. In animals exposed to 1 mg/kg/day, similar concentration of DON was found in GD 18 dam plasma and fetuses, demonstrating significant gestational transfer. The concentration of DON in PND 4 dam plasma was similar to that in GD 18 dam plasma. However, DON was not detected in PND 4 pup plasma above the limit of detection of the assay, demonstrating absence of transfer of DON to pups via lactation.

Determination of Urinary Mycotoxin Biomarkers Using a Sensitive Online Solid Phase Extraction-UHPLC-MS/MS Method

In the course of assessing the human exposure to mycotoxins, biomarker-based approaches have proven to be important tools. Low concentration levels, complex matrix compositions, structurally diverse analytes, and the large size of sample cohorts are the main challenges of analytical procedures. For that reason, an online solid phase extraction-ultra high-performance liquid chromatography-tandem mass spectrometry (online SPE-UHPLC-MS/MS) method was developed, allowing for the sensitive, robust, and rapid analysis of 11 relevant mycotoxins and mycotoxin metabolites in human urine. The included spectrum of analytes comprises aflatoxin M₁ (AFM₁), altenuene (ALT), alternariol monomethyl ether (AME), alternariol (AOH), citrinin (CIT) and its metabolite dihydrocitrinone (DH-CIT), fumonisin B₁ (FB₁), ochratoxin A (OTA), and zearalenone (ZEN) as well as α- and β-zearalenol (α- and β-ZEL). Reliable quantitation was achieved by means of stable isotope dilution, except for ALT, AME and AOH using matrix calibrations. The evaluation of method performance displayed low limits of detection in the range of pg/mL urine, satisfactory apparent recovery rates as well as high accuracy and precision during intra- and interday repeatability. Within the analysis of Zimbabwean urine samples (n = 50), the applicability of the newly developed method was shown. In addition to FB₁ being quantifiable in all analyzed samples, six other mycotoxin biomarkers were detected. Compared to the occurrence rates obtained after analyzing the same sample set using an established dilute and shoot (DaS) approach, a considerably higher number of positive samples was observed when applying the online SPE method. Owing to the increased sensitivity, less need of sample handling, and low time effort, the herein presented online SPE approach provides a valuable contribution to human biomonitoring of mycotoxin exposure.

Case-Control Study of Nodding Syndrome in Acholiland: Urinary Multi-Mycotoxin Screening

This case-control study adds to the growing body of knowledge on the medical, nutritional, and environmental factors associated with Nodding Syndrome (NS), a seizure disorder of children and adolescents in northern Uganda. Past research described a significant association between NS and prior history of measles infection, dependence on emergency food and, at head nodding onset, subsistence on moldy maize, which has the potential to harbor mycotoxins. We used LC-MS/MS to screen for current mycotoxin loads by evaluating nine analytes in urine samples from age-and-gender matched NS cases (n = 50) and Community Controls (CC, n = 50). The presence of the three mycotoxins identified in the screening was not significantly different between the two groups, so samples were combined to generate an overall view of exposure in this community during the study. Compared against subsequently run standards, α-zearalenol (43 ± 103 µg/L in 15 samples > limit of quantitation (LOQ); 0 (0/359) µg/L), T-2 toxin (39 ± 81 µg/L in 72 samples > LOQ; 0 (0/425) µg/L) and aflatoxin M1 (4 ± 10 µg/L in 15 samples > LOQ; 0 (0/45) µg/L) were detected and calculated as the average concentration ± SD; median (min/max). Ninety-five percent of the samples had at least one urinary mycotoxin; 87% were positive for two of the three compounds detected. While mycotoxin loads at NS onset years ago are and will remain unknown, this study showed that children with and without NS currently harbor foodborne mycotoxins, including those associated with maize.

Biomonitoring of Multiple Mycotoxins in Urine by GC-MS/MS: A Pilot Study on Patients with Esophageal Cancer in Golestan Province, Northeastern Iran

A pilot study to investigate the occurrence of 10 mycotoxins (deoxynivalenol, DON; 3-acetyldeoxynivalenol, 3-ADON; 15-acetyldeoxynivalenol, 15-ADON; fusarenon-X, FUS-X; diacetoxyscirpenol, DAS; nivalenol, NIV; neosolaniol, NEO; zearalenone, ZON; zearalanone, ZAN; T-2 toxin, T-2; and HT-2 toxin, HT-2) in esophageal cancer patients was performed with the urinary biomarkers approach in Golestan, Iran. Urine multimycotoxin analysis was performed by dispersive liquid–liquid microextraction and gas chromatography–tandem mass spectrometry (GC–MS/MS) analysis, and values were normalized with urinary creatinine (μg/g). Four mycotoxins, namely NEO (40%), HT-2 (17.6%), DON (10%), and HT-2 (5.8%), were detected in the analyzed urine samples. DON was only detected in the control group (5.09 μg/g creatinine), while T-2 (44.70 μg/g creatinine) was only present in the esophageal cancer group. NEO and HT-2 were quantified in both control and case groups, showing average of positive samples of 9.09 and 10.45 μg/g creatinine for NEO and 16.81 and 29.09 μg/g creatinine for HT-2, respectively. Mycotoxin co-occurrence was observed in three samples as binary (NEO/HT-2 and T-2/HT-2) and ternary (DON/NEO/HT-2) combinations, reaching total concentrations of 44.58, 79.13, and 30.04 µg/g creatinine, respectively. Further investigations are needed to explore a causal association between mycotoxin contamination and esophageal cancer. For this pilot study in Golestan, the low sample size was a very limiting factor.

Dried urine spots as sampling technique for multi-mycotoxin analysis in human urine

A simple and effective approach for HPLC-MS/MS based multi-mycotoxin analysis in human urine samples was developed by application of dried urine spots (DUS) as alternative on-site sampling strategy. The newly developed method enables the detection and quantitation of 14 relevant mycotoxins and mycotoxin metabolites, including citrinin (CIT), dihydrocitrinone (DH-CIT), deoxynivalenol (DON), fumonisin B₁ (FB₁), T-2 Toxin (T-2), HT-2 Toxin (HT-2), ochratoxin A (OTA), 2′R-ochratoxin A (2′R-OTA), ochratoxin α (OTα), tenuazonic acid and allo-tenuazonic acid (TeA + allo-TeA), zearalenone (ZEN), zearalanone (ZAN), α-zearalenol (α-ZEL), and β-zearalenol (β-ZEL). Besides the spotting procedure, sample preparation includes enzymatic cleavage of glucuronic acid conjugates and stable isotope dilution analysis. Method validation revealed low limits of detection in the range of pg/mL urine and excellent apparent recovery rates for most analytes. Stability investigation of DUS displayed no or only slight decrease of the analyte concentration over a period of 28 days at room temperature. The new method was applied to the analysis of a set of urine samples (n = 91) from a Swedish cohort. The four analytes, DH-CIT, DON, OTA, and TeA + allo-TeA, could be detected and quantified in amounts ranging from 0.06 to 0.97 ng/mL, 3.03 to 136 ng/mL, 0.013 to 0.434 ng/mL and from 0.36 to 47 ng/mL in 38.5%, 70.3%, 68.1%, and 94.5% of the samples, respectively. Additional analysis of these urine samples with an established dilute and shoot (DaS) approach displayed a high consistency of the results obtained with both methods. However, due to higher sensitivity, a larger number of positive samples were observed using the DUS method consequently providing a suitable approach for human biomonitoring of mycotoxin exposure.

Mycotoxins-Biomonitoring and Human Exposure

Mycotoxins are secondary metabolites produced by fungal species that commonly have a toxic effect on human and animal health. Different foodstuff can be contaminated and are considered the major source of human exposure to mycotoxins, but occupational and environmental exposure can also significantly contribute to this problem. This review aims to provide a short overview of the occurrence of toxigenic fungi and regulated mycotoxins in foods and workplaces, following the current literature and data presented in scientific papers. Biomonitoring of mycotoxins in plasma, serum, urine, and blood samples has become a common method for determining the exposure to different mycotoxins. Novel techniques are more and more precise and accurate and are aiming toward the simultaneous determination of multiple mycotoxins in one analysis. Application of liquid chromatography (LC) methodologies, coupled with tandem mass spectrometry (MS/MS) or high-resolution mass spectrometry (HRMS) has become a common and most reliable method for determining the exposure to mycotoxins. Numerous references confirm the importance of mycotoxin biomonitoring to assess the exposure for humans and animals. The objectives of this paper were to review the general approaches to biomonitoring of different mycotoxins and the occurrence of toxigenic fungi and their mycotoxins, using recent literature sources.

Presence of 19 Mycotoxins in Human Plasma in a Region of Northern Spain

This study was conducted to investigate human exposure to 19 compounds (mycotoxins and their metabolites) in plasma samples from healthy adults (n = 438, aged 19-68 years) from Navarra, a region of northern Spain. Samples were analyzed by LC-MS/MS, before and after enzymatic hydrolysis for the detection of possible glucuronides and/or sulfates (Phase II metabolites). The most prevalent mycotoxin was ochratoxin A (OTA), with an incidence of 97.3%. Positive samples were in the concentration range of 0.4 ng/mL to 45.7 ng/mL. After enzymatic treatment, OTA levels increased in a percentage of individuals, which may indicate the presence of OTA-conjugates. Regarding ochratoxin B, it has also been detected (10% of the samples), and its presence may be related to human metabolism of OTA. Sterigmatocystin was detected with a high incidence (85.8%), but only after enzymatic hydrolysis, supporting glucuronidation as a pathway of its metabolism in humans. None of the other studied mycotoxins (aflatoxins B1, B2, G1, G2 and M1; T-2 and HT-2 toxins; deoxynivalenol, deepoxy-deoxynivalenol, 3-acetyldeoxynivalenol, 15-acetyldeoxynivalenol; zearalenone; nivalenol; fusarenon-X; neosolaniol; and diacetoxyscirpenol) were detected in any of the samples, neither before nor after enzymatic treatment. To the best of our knowledge, this is the first report carried out in Spain to determine the exposure of the population to mycotoxins and some of their metabolites using plasma, and the obtained results justify the need for human biomonitoring and metabolism studies on mycotoxins.

Improved methods for biomarker analysis of the big five mycotoxins enables reliable exposure characterization in a population of childbearing age women in Rwanda

Of the five agriculturally important mycotoxins, AFB₁, FB₁, DON, ZEA and OTA, a well-characterized biomarker of exposure in blood is only available for aflatoxin. Working with a population of 139 women of childbearing age in Rwanda, we undertook a comprehensive assessment of their dietary mycotoxin exposure. Using high-resolution LC-MS/MS with stable isotope dilution analysis, the albumin-aflatoxin adduct was quantitated in plasma. Similarly, AFM₁, AFB₁, AFG₁, FB₁ and B₂, OTA, zearalenone, α-zearalenol, deoxynivalenol, deoxynivalenol-15-glucuronide and deoxynivalenol-3-glucuronide were quantitated in urine. AFB₁-Lys was detected in plasma from 81% of the women, indicative of exposures 1-2 orders of magnitude above current guidance. Zearalenone and/or α-zearalenol were detected in the urine of 61% of the women, the majority of whom had estimated exposures 2-5 times the PMTDI, with one third more than an order of magnitude above. Urinary deoxynivalenol or the two glucuronide conjugates were found in 77% of the participants. Of these, 60% were below the PMTDI, 28% were twice and 12% were >10x the PMTDI. Fumonisin B₁ (30%) and ochratoxin A (71%) were also detected in urine. Exposures observed in these Rwandan women raise serious food safety concerns and highlight the need for authorities to help manage multiple mycotoxins in their diet.

Microfiltration results in the loss of analytes and affects the in vitro genotoxicity of a complex mixture of Alternaria toxins

Alternaria molds produce a variety of chemically diverse secondary metabolites with potentially adverse effects on human health. However, data on occurrence in food and human exposure is inconsistent for some of these mycotoxins. Membrane filtration is a frequent step in many sample preparation procedures for LC-MS-based methods analyzing food contaminants. Yet, little is known about the possibility of adsorptive phenomena that might result in analyte losses. Thus, we treated a complex extract of Alternaria toxins with several types of syringe filters and unraveled the impact on its chemical composition by LC-MS/MS. We observed significant, and in some cases complete, losses of compounds due to filtration. Particularly, two key Alternaria toxins, alternariol (AOH) and its monomethyl ether (AME), were heavily affected. As a comparison with published food surveys indicating a correlation of the type of filtration used with lower incidence reports in food, our results point at a possible underestimation of AME in past exposure assessment. Also, perylene quinones were greatly affected by filtration, underlining the importance to take this into consideration during analytical method development. Furthermore, we applied the comet assay in HT-29 cells to elucidate the impact of filtration on the genotoxicity of the extract. We observed strong coincidences with the loss of epoxide-carrying metabolites and also an intriguing induction of oxidative DNA damage by yet toxicologically uncharacterized Alternaria toxins. In conclusion, we highlight potential issues with sample filtration and call for a critical re-evaluation of previous food occurrence data in the light of the results at hand.

Pro-Inflammatory Effects of NX-3 Toxin Are Comparable to Deoxynivalenol and not Modulated by the Co-Occurring Pro-Oxidant Aurofusarin

The type A trichothecene NX-3, produced by certain Fusarium graminearum strains, is similar to the mycotoxin deoxynivalenol (DON), with the exception that it lacks the carbonyl moiety at the C-8 position. NX-3 inhibits protein biosynthesis and induces cytotoxicity to a similar extent as DON, but so far, immunomodulatory effects have not been assessed. In the present study, we investigated the impact of NX-3 on the activity of the nuclear factor kappa B (NF-κB) signaling pathway in direct comparison to DON. Under pro-inflammatory conditions (IL-1β treatment), the impact on cytokine mRNA levels of NF-κB downstream genes was studied in human colon cell lines, comparing noncancer (HCEC-1CT) and cancer cells (HT-29). In addition, potential combinatory effects with the co-occurring Fusarium secondary metabolite aurofusarin (AURO), a dimeric naphthoquinone known to induce oxidative stress, were investigated. NX-3 and DON (1&nbsp;μM, 20 h) significantly activated a NF-κB regulated reporter gene to a similar extent. Both trichothecenes also enhanced transcript levels of the known NF-κB-dependent pro-inflammatory cytokines IL-8, IL-6, TNF-α and IL-1β. Comparing the colon cancer HT-29 and noncancer HCEC-1CT cells, significant differences in cytokine signaling were identified. In contrast, AURO did not affect NF-κB pathway activity and respective cytokine expression levels at the tested concentration. Despite its pro-oxidant potency, the combination with AURO did not significantly affect the immunomodulatory effects of the tested trichothecenes. Taken together, the present study reveals comparable potency of DON and NX-3 with respect to immunomodulatory and pro-inflammatory potential. Consequently, not only DON but also NX-3 should be considered as factors contributing to intestinal inflammatory processes.

Aptamer-Based Biosensor for Detection of Mycotoxins

Mycotoxins are a large type of secondary metabolites produced by fungi that pose a great hazard to and cause toxic reactions in humans and animals. A majority of countries and regulators, such as the European Union, have established a series of requirements for their use, and they have also set maximum tolerance levels. The development of high sensitivity and a specific analytical platform for mycotoxins is much in demand to address new challenges for food safety worldwide. Due to the superiority of simple, rapid, and low-cost characteristics, aptamer-based biosensors have successfully been developed for the detection of various mycotoxins with high sensitivity and selectivity compared with traditional instrumental methods and immunological approaches. In this article, we discuss and analyze the development of aptasensors for mycotoxins determination in food and agricultural products over the last 11 years and cover the literatures from the first report in 2008 until the present time. In addition, challenges and future trends for the selection of aptamers toward various mycotoxins and aptasensors for multi-mycotoxins analyses are summarized. Given the promising development and potential application of aptasensors, future research studies made will witness the great practicality of using aptamer-based biosensors within the field of food safety.

Development of a Sensitive and Reliable UHPLC-MS/MS Method for the Determination of Multiple Urinary Biomarkers of Mycotoxin Exposure

A variety of mycotoxins from different sources frequently contaminate farm products, presenting a potential toxicological concern for animals and human. Mycotoxin exposure has been the focus of attention for governments around the world. To date, biomarkers are used to monitor mycotoxin exposure and promote new understanding of their role in chronic diseases. The goal of this research was to develop and validate a sensitive UHPLC-MS/MS method using isotopically-labeled internal standards suitable for accurate determination of 18 mycotoxin biomarkers, including fumonisins, ochratoxins, Alternaria and emerging Fusarium mycotoxins (fumonisin B1, B2, and B3, hydrolyzed fumonisin B1 and B2, ochratoxin A, B, and alpha, alternariol, alternariol monomethyl ether, altenuene, tentoxin, tenuazonic acid, beauvericin, enniatin A, A1, B, and B1) in human urine. After enzymatic digestion with β-glucuronidase, human urine samples were cleaned up using HLB solid phase extraction cartridges prior to instrument analysis. The multi-mycotoxin and analyte-specific method was validated in-house, providing satisfactory results. The method provided good linearity in the tested concentration range (from LOQ up to 25-500 ng/mL for different analytes), with R2 from 0.997 to 0.999. The limits of quantitation varied from 0.0002 to 0.5 ng/mL for all analytes in urine. The recoveries for spiked samples were between 74.0% and 133%, with intra-day precision of 0.5%-8.7% and inter-day precision of 2.4%-13.4%. This method was applied to 60 urine samples collected from healthy volunteers in Beijing, and 10 biomarkers were found. At least one biomarker was found in all but one of the samples. The high sensitivity and accuracy of this method make it practical for human biomonitoring and mycotoxin exposure assessment.

Multimycotoxin Exposure Assessment in UK Children Using Urinary Biomarkers-A Pilot Survey

Cereal foods are commonly contaminated with multiple mycotoxins resulting in frequent human mycotoxin exposure. Children are at risk of high-level exposure because of their high cereal intake relative to body weight. Hence, this study aims to assess multimycotoxin exposure in UK children using urinary biomarkers. Spot urines (n = 21) were analyzed for multimycotoxins (deoxynivalenol, DON; nivalenol, NIV; ochratoxin A, OTA; zearalenone, ZEN; α-zearalenol, α-ZEL; β-zearalenol, β-ZEL; T-2 toxin, T-2; HT-2 toxin, HT-2; and aflatoxin B₁ and M_1, AFB₁, AFM₁) using liquid chromatography-coupled tandem mass spectrometry. Urine samples frequently contained DON (13.10 ± 12.69 ng/mL), NIV (0.36 ± 0.16 ng/mL), OTA (0.05 ± 0.02 ng/mL), and ZEN (0.09 ± 0.07 ng/mL). Some samples (1-3) contained T-2, HT-2, α-ZEL, and β-ZEL but not aflatoxins. Dietary mycotoxin estimation showed that children were frequently exposed to levels exceeding the tolerable daily intake (52 and 95% of cases for DON and OTA). This demonstrates that UK children are exposed to multiple mycotoxins through their habitual diet.

A semiconductor quantum dot-based ratiometric electrochemical aptasensor for the selective and reliable determination of aflatoxin B1

In recent years, a ratiometric electrochemical method has been investigated due to its ability to effectively reduce the background electrical signals via the introduction of an internal calibration mechanism, which has great practical significance in the detection of mycotoxins in foods. Herein, we report a ratiometric electrochemical aptasensor based on two semiconductor quantum dots (i.e. CdTe and PbS QDs) for the detection of aflatoxin B1 (AFB1). The aptasensor was fabricated by immobilizing PbS QD-coated silica hybrid spheres (SiO2@PbS) onto CdTe QD-modified Fe3O4@SiO2 (Fe3O4@SiO2/CdTe) surface through biorecognition between the aptamer and complementary DNAs, where PbS QDs acted as external signal labels and CdTe QDs acted as internal reference labels. In the presence of AFB1, the aptamer connected to SiO2@PbS preferred to form an aptamer/AFB1 complex, which brought about the separation of SiO2@PbS linked with the CdTe QDs; with the addition of more AFB1 to the solution, the amount of SiO2@PbS present on the Fe3O4@SiO2/CdTe surface reduced. After several steps of endonuclease cleavage, magnetic separation, and dissolution with acid, the square wave voltammetry signals of Pb2+ and Cd2+ maintained an inverse relationship with the target content based on the SWV stripping measurements; the proposed method had the wide linear range of 5 pg mL-1-50 ng mL-1 and the determination limit of 4.5 pg mL-1 (S/N = 3) and was applied for the detection of AFB1 in peanuts. The proposed aptasensor has an important practical significance for the development of food safety.

Occupational Exposure to Mycotoxins: Current Knowledge and Prospects

Occupational exposure to mycotoxins is supposedly very frequent, but it is rarely reported in the scientific literature. Several recent studies described occupational exposure to the aflatoxin B1 (AFB1) mycotoxin in different occupational settings. Previously, exposure to other mycotoxins was shown in the animal husbandry and food processing sectors, confirming that occupational exposure cannot be negligible. However, no guidelines or standard methodologies are available for helping occupational hygienists to consider mycotoxin exposure in their interventions. This article reviews the literature on this problem and recommends some actions for the better management of this risk factor in occupational settings, especially where environmental conditions are favorable to fungal presence.

The Fusarium metabolite culmorin suppresses the in vitro glucuronidation of deoxynivalenol

Glucuronidation is a major phase II conjugation pathway in mammals, playing an important role in the detoxification and biotransformation of xenobiotics including mycotoxins such as deoxynivalenol (DON). Culmorin (CUL), a potentially co-occurring Fusarium metabolite, was recently found to inhibit the corresponding detoxification reaction in plants, namely DON-glucoside formation, raising the question whether CUL might affect also the mammalian counterpart. Using cell-free conditions, CUL when present equimolar (67 µM) or in fivefold excess, suppressed DON glucuronidation by human liver microsomes, reducing the formation of DON-15-glucuronide by 15 and 50%, and DON-3-glucuronide by 30 and 50%, respectively. Substantial inhibitory effects on DON glucuronidation up to 100% were found using the human recombinant uridine 5'-diphospho-glucuronosyltransferases (UGT) 2B4 and 2B7, applying a tenfold excess of CUL (100 µM). In addition, we observed the formation of a novel metabolite of CUL, CUL-11-glucuronide, identified for the first time in vitro as well as in vivo in piglet and human urine samples. Despite the observed potency of CUL to inhibit glucuronidation, no significant synergistic toxicity on cell viability was observed in combinations of CUL (0.1-100 µM) and DON (0.01-10 µM) in HT-29 and HepG2 cells, presumably reflecting the limited capacity of the tested cell lines for DON glucuronidation. However, in humans, glucuronidation is known to represent the main detoxification pathway for DON. The present results, including the identification of CUL-11-glucuronide in urine samples of piglets and humans, underline the necessity of further studies on the relevance of CUL as a potentially co-occurring modulator of DON toxicokinetics in vivo.

The effect of individual and mixtures of mycotoxins and persistent organochloride pesticides on oestrogen receptor transcriptional activation using in vitro reporter gene assays

The mycotoxins zearalenone (ZEN) and alpha-zearalenone (α-ZOL), which are common contaminants of agri-food products, are known for their oestrogenic potential. In addition to mycotoxins, food may also contain pesticides with oestrogenic properties such as 1,1,1-trichloro-2,2-bis(p-chlorophenyl) ethane (p,p'-DDT) and 1,1-dichloro-2,2-bis(p-chlorophenyl) ethylene (p,p'-DDE), raising the question on the potential effects of individual and combinations of these xeno-oestrogens on the action of natural oestrogens. The present study employed a mammalian reporter gene assay to assess the effects individual and binary combinations of these environmental and food-borne contaminants on oestrogen nuclear receptor (ER) transactivation. As expected, α-ZOL and ZEN exhibited the strongest oestrogenic potency (EC₅₀: 0.27 ± 0.121 nM and 1.32 ± 0.0956 nM, respectively) whereas p,p'-DDT and p,p'-DDE had weak ER agonistic activity with the maximal response of 28.70 ± 2.97% and 18.65 ± 1.77%, respectively. Concurrent treatment of the mycotoxins and/or pesticides, individually or in binary combination, with 17β-oestradiol (E₂) showed either additive, synergistic or antagonistic interactive effects on E₂-mediated ER response, depending on the combination ratios, the concentration range of xeno-oestrogens, and the concentration of E₂. This study highlights the importance of assessing the mixture effects of chemical contaminants in risk assessment, especially in the area of reproductive and developmental toxicity.

Interactions of food matrix and dietary components on neonicotinoid bioaccessibility in raw fruit and vegetables

Humans are frequently exposed to the residues of various neonicotinoids, highlighting the need to understand human exposure through oral ingestion of contaminated foods. In this study, the effects of different food matrices (tomato, cucumber, and carrot) and their interaction with dietary component additives, including proteins and dietary fiber, was investigated. The results showed that the presence of a food matrix had a significant effect on the bioaccessibility of neonicotinoids (imidacloprid, thiamethoxam, acetamiprid, and thiacloprid) in both the gastric and intestinal environments. Neonicotinoids in tomato presented relatively low bioaccessibility, indicating that the daily intake of the tomato can be regarded as being relatively safer. Moreover, the addition of protein or dietary fiber to fruit and vegetables had a marked influence on neonicotinoid bioaccessibility and the effects varied between the different matrices. In particular, the addition of 2.0% dietary fiber significantly reduced the bioaccessibility (18.38-67.91%). Therefore, we recommend that consuming an increased intake of dietary fiber could improve the safety of fruit and vegetables in daily life. The present results can support the identification of suitable food intake conditions for the significant reduction of pesticide residue levels.

Mycotoxins in uncooked and plate-ready household food from rural northern Nigeria

In order to understand the changes in toxic metabolite profiles in uncooked and cooked foods, samples of flour/grain (n = 40) and their corresponding plate-ready food (n = 39) were collected from 40 households in two states of northern Nigeria. The food samples were analyzed for multiple fungal metabolites by LC-MS/MS and daily intakes of mycotoxins in the diets were estimated and compared to established margin of exposure (MOE) and tolerable daily intake (TDI) values. Both food groups contained 65 fungal and plant metabolites, inclusive of 23 mycotoxins. The mean concentrations of aflatoxin B₁, beauvericin, fumonisin B₁ (FB₁), FB₂, FB₃, hydrolysed FB₁, moniliformin and nivalenol were significantly (p < 0.05) higher in flour than in the plate-ready food samples. The levels of several mycotoxins were higher in the flour samples than in plate-ready meals by 129-383%. The dilution effect from proportionate mixing of flour samples with water led to 48-100% reduction in detectable mycotoxins in flour to plate-ready meals. Aflatoxins and fumonisins co-occurred in 36% of the plate-ready foods. Exposures of households to aflatoxins and fumonisins based on 95% CI concentration of mycotoxins in the meals were high, suggesting potential health risks based on calculated low MOE and exceedence of stipulated TDI value, respectively.

Occupational Exposure to Mycotoxins in Swine Production: Environmental and Biological Monitoring Approaches

Swine production workers are exposed simultaneously to multiple contaminants. Occupational exposure to aflatoxin B₁ (AFB₁) in Portuguese swine production farms has already been reported. However, besides AFB₁, data regarding fungal contamination showed that exposure to other mycotoxins could be expected in this setting. The present study aimed to characterize the occupational exposure to multiple mycotoxins of swine production workers. To provide a broad view on the burden of contamination by mycotoxins and the workers' exposure, biological (urine) samples from workers (n = 25) and 38 environmental samples (air samples, n = 23; litter samples, n = 5; feed samples, n = 10) were collected. The mycotoxins biomarkers detected in the urine samples of the workers group were the deoxynivalenol-glucuronic acid conjugate (60%), aflatoxin M₁ (16%), enniatin B (4%), citrinin (8%), dihydrocitrinone (12%) and ochratoxin A (80%). Results of the control group followed the same pattern, but in general with a lower number of quantifiable results ( Collapse

Key Words

• biomonitoring
• mycotoxins
• mycotoxins mixture
• occupational exposure
• swine production

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MESH Headings

• Adult
• Air Pollutants/analysis
• Air Pollutants/urine
• Animal Feed/analysis
• Animal Husbandry
• Animals
• Biomarkers/urine
• Environmental Monitoring
• Feces/chemistry
• Female
• Food Contamination/analysis
• Humans
• Male
• Middle Aged
• Mycotoxins/analysis
• Mycotoxins/urine
• Occupational Exposure/analysis
• Portugal
• Swine

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Affiliation(s)

Susana Viegas H&TRC-Health & Technology Research Center, ESTeSL-Escola Superior de Tecnologia da Saúde, Instituto Politécnico de Lisboa, 1990-096 Lisbon, Portugal. Centro de Investigação em Saúde Pública, Escola Nacional de Saúde Pública, Universidade NOVA de Lisboa, 1600-560 Lisbon, Portugal.
Ricardo Assunção Food and Nutrition Department, National Institute of Health Doutor Ricardo Jorge, I.P. (INSA), Av. Padre Cruz, 1649-016 Lisbon, Portugal. Centre for Environmental and Marine Studies (CESAM), University of Aveiro, Campus de Santiago, 3810-193 Aveiro, Portugal.
Carla Martins Centro de Investigação em Saúde Pública, Escola Nacional de Saúde Pública, Universidade NOVA de Lisboa, 1600-560 Lisbon, Portugal. Food and Nutrition Department, National Institute of Health Doutor Ricardo Jorge, I.P. (INSA), Av. Padre Cruz, 1649-016 Lisbon, Portugal. Centre for Environmental and Marine Studies (CESAM), University of Aveiro, Campus de Santiago, 3810-193 Aveiro, Portugal. Escola Nacional de Saúde Pública, Universidade NOVA de Lisboa, 1600-560 Lisbon, Portugal.
Carla Nunes Centro de Investigação em Saúde Pública, Escola Nacional de Saúde Pública, Universidade NOVA de Lisboa, 1600-560 Lisbon, Portugal. Escola Nacional de Saúde Pública, Universidade NOVA de Lisboa, 1600-560 Lisbon, Portugal.
Bernd Osteresch Group of Prof. Humpf, Institute of Food Chemistry, Westfälische Wilhelms-Universität Münster Corrensstraße 45, 48149 Münster, Germany.
Magdalena Twarużek Faculty of Natural Sciences, Institute of Experimental Biology, Department of Physiology and Toxicology, Kazimierz Wielki University, 85-064 Bydgoszcz, Poland.
Robert Kosicki Faculty of Natural Sciences, Institute of Experimental Biology, Department of Physiology and Toxicology, Kazimierz Wielki University, 85-064 Bydgoszcz, Poland.
Jan Grajewski Faculty of Natural Sciences, Institute of Experimental Biology, Department of Physiology and Toxicology, Kazimierz Wielki University, 85-064 Bydgoszcz, Poland.
Edna Ribeiro H&TRC-Health & Technology Research Center, ESTeSL-Escola Superior de Tecnologia da Saúde, Instituto Politécnico de Lisboa, 1990-096 Lisbon, Portugal.
Carla Viegas H&TRC-Health & Technology Research Center, ESTeSL-Escola Superior de Tecnologia da Saúde, Instituto Politécnico de Lisboa, 1990-096 Lisbon, Portugal. Centro de Investigação em Saúde Pública, Escola Nacional de Saúde Pública, Universidade NOVA de Lisboa, 1600-560 Lisbon, Portugal.

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Exposure Assessment to Mycotoxins in a Portuguese Fresh Bread Dough Company by Using a Multi-Biomarker Approach

Mycotoxins are toxic mold metabolites that can persist in environment long after the fungi species responsible for their production disappear. Critical workplace for mycotoxins presence has already been studied and nowadays it is possible to recognize that exposure to mycotoxins through inhalation occurs due to their presence in dust. This study aimed to assess occupational co-exposure to multiple mycotoxins in a fresh bread dough company, an occupational setting not studied until now. Occupational exposure assessment to mycotoxins was done using a LC-MS/MS urinary multi-biomarker approach. Twenty-one workers and nineteen individuals that were used as controls participated in the study. Workers/controls (spot-urine) and environment (settled dust) samples were collected and analyzed. Concerning workers group, DON-GlcA, and OTA were the most prevalent biomarkers (>LOD), 66% and 90.5%, respectively. In the control group, OTA was also one of the most detected (68%) followed by CIT (58%) and DON-GlcA (58%). DON was the mycotoxin measured in high amounts in the settled dust sample (58.2 ng/g). Both workers and controls are exposed to several mycotoxins simultaneously. The workers group, due to their high contact with flour dust, revealed a higher exposure to DON. Considering these results, risk management measures must be applied including specific and adequate health surveillance programs in order to avoid exposure and consequently the associated health consequences.

Study of Factors Influencing the Bioaccessibility of Triazolone in Cherry Tomatoes Using a Static SHIME Model

Estimating the influence of bioaccessibility of pesticide residues in fruits and vegetables on dietary exposure is a challenge for human health risk assessment. This study investigated the bioaccessibility of pesticide residues in cherry tomatoes and contributing factors (digestion time, pH, solid/liquid ratio, and dietary nutrition) using an in vitro test simulating the human gastrointestinal tract. pH had the largest effect on triazolone precipitation in the simulated gastric intestinal juice, which had a significant impact on the bioaccessibility. The bioaccessibility of triazolone in the intestinal stage was slightly higher than that in the stomach stage, owing to bile salts and pancreatic enzymes present in the intestinal juice. The bioaccessibility of triazolone did not change significantly with digestion time. In the gastric stage, there was a logarithmic relationship between the bioaccessibility and solid/liquid ratio (R² = 0.9941). The addition of oil significantly changed the bioaccessibility in the gastrointestinal stage. Protein and dietary fiber only affected bioaccessibility in the stomach stage. Dietary nutrition can reduce the release of pesticides from fruits and vegetables into the stomach, sharply reducing the bioaccessibility, and the dietary exposure of pesticide residues in fruits and vegetables can be properly evaluated.

Fabrication of magnetically assembled aptasensing device for label-free determination of aflatoxin B1 based on EIS

Aflatoxin B1 (AFB1), one of the most common mycotoxins in food matrixes, has been identified as the most toxic contaminant with mutagenic, teratogenic, immunosuppressive, and carcinogenic effects. In this work, a magnetically assembled aptasensing device has been designed for label-free determination of AFB1 by employing a disposable screen-printed carbon electrode (SPCE) covered with a designed polydimethylsiloxane (PDMS) film as the micro electrolytic cell. The magnetically controlled bio-probes were firstly prepared by immobilization of the thiolated aptamers on the Fe₃O₄@Au magnetic beads, which was rapidly assembled on the working electrode of SPCE within 10 s, by using a magnet placed at the opposite side. The PDMS film with a centered hole was covered on the SPCE surface to achieve a more practicable and flexible electrochemical measurement. In this effort, a label-free aptasensor for the sensitive and selective determination of AFB1 has been developed using electrochemical impedance spectroscopy upon the biorecognition between aptamers and the targets. The developed method had a wide linear range of 20 pg mL^-1-50 ng mL^-1 with a detection limit of 15 pg mL^-1 (S/N = 3) and succeeded in spiked samples of peanuts. The developed aptasensing device shows fantastic application prospect with simple design, easy operation, low cost, and high sensitivity and selectivity characteristics. This sensing strategy represents a promising path toward routine quality control of food safety and creates the opportunity to develop facile aptasensing device for other targets.

Assessment of Urinary Deoxynivalenol Biomarkers in UK Children and Adolescents

Deoxynivalenol (DON), the mycotoxin produced mainly by Fusarium graminearum and found in contaminated cereal-based foodstuff, has been consistently detected in body fluids in adults. Available data in children and adolescents are scarce. This study assessed urinary DON concentrations in children aged 3-9 years (n = 40) and adolescents aged 10-17 years (n = 39) in the UK. Morning urine samples were collected over two consecutive days and analysed for free DON (un-metabolised form), DON-glucuronides (DON-GlcA), deepoxy deoxynivalenol (DOM-1), and total DON (sum of free DON, DON-GlcA, and DOM-1). Total DON was detected in the urine of >95% of children and adolescents on both days. Mean total DON concentrations (ng/mg creatinine) were 41.6 and 21.0 for children and adolescents, respectively. The greatest total DON levels were obtained in female children on both days (214 and 219 ng/mg creatinine on days 1 and 2, respectively). Free DON and DON-GlcA were detected in most urine specimens, whereas DOM-1 was not present in any sample. Estimation of dietary DON exposure suggested that 33-63% of children and 5-46% of adolescents exceeded current guidance regarding the maximum provisional tolerable daily intake (PMTDI) for DON. Although moderate mean urinary DON concentrations were shown, the high detection frequency of urinary DON, the maximum biomarker concentrations, and estimated dietary DON exposure are concerning.

High resolution-ion mobility mass spectrometry as an additional powerful tool for structural characterization of mycotoxin metabolites

This work was designed as a proof of concept, to demonstrate the successful use of the comparison between theoretical and experimental collision cross section (CCS) values to support the identification of isomeric forms. To this purpose, thirteen mycotoxins were considered and analyzed using drift time ion mobility mass spectrometry. A good linear correlation (r² = 0.962) between theoretical and experimental CCS was found. The average ΔCCS was 3.2%, fully consistent with the acceptability threshold value commonly set at 5%. The agreement between theoretical and experimental CCS obtained for mycotoxin glucuronides suggested the potential of the CCS matching in supporting the annotation procedure.

Mycotoxin Analysis of Human Urine by LC-MS/MS: A Comparative Extraction Study

The lower mycotoxin levels detected in urine make the development of sensitive and accurate analytical methods essential. Three extraction methods, namely salting-out liquid–liquid extraction (SALLE), miniQuEChERS (quick, easy, cheap, effective, rugged, and safe), and dispersive liquid–liquid microextraction (DLLME), were evaluated and compared based on analytical parameters for the quantitative LC-MS/MS measurement of 11 mycotoxins (AFB1, AFB2, AFG1, AFG2, OTA, ZEA, BEA, EN A, EN B, EN A1 and EN B1) in human urine. DLLME was selected as the most appropriate methodology, as it produced better validation results for recovery (79–113%), reproducibility (RSDs < 12%), and repeatability (RSDs < 15%) than miniQuEChERS (71–109%, RSDs <14% and <24%, respectively) and SALLE (70–108%, RSDs < 14% and < 24%, respectively). Moreover, the lowest detection (LODS) and quantitation limits (LOQS) were achieved with DLLME (LODs: 0.005–2 μg L⁻¹, LOQs: 0.1–4 μg L⁻¹). DLLME methodology was used for the analysis of 10 real urine samples from healthy volunteers showing the presence of ENs B, B1 and A1 at low concentrations.

Studies on the Presence of Mycotoxins in Biological Samples: An Overview

Mycotoxins are fungal secondary metabolites with bioaccumulation levels leading to their carry-over into animal fluids, organs, and tissues. As a consequence, mycotoxin determination in biological samples from humans and animals has been reported worldwide. Since most mycotoxins show toxic effects at low concentrations and considering the extremely low levels present in biological samples, the application of reliable detection methods is required. This review summarizes the information regarding the studies involving mycotoxin determination in biological samples over the last 10 years. Relevant data on extraction methodology, detection techniques, sample size, limits of detection, and quantitation are presented herein. Briefly, liquid-liquid extraction followed by LC-MS/MS determination was the most common technique. The most analyzed mycotoxin was ochratoxin A, followed by zearalenone and deoxynivalenol—including their metabolites, enniatins, fumonisins, aflatoxins, T-2 and HT-2 toxins. Moreover, the studies were classified by their purpose, mainly focused on the development of analytical methodologies, mycotoxin biomonitoring, and exposure assessment. The study of tissue distribution, bioaccumulation, carry-over, persistence and transference of mycotoxins, as well as, toxicokinetics and ADME (absorption, distribution, metabolism and excretion) were other proposed goals for biological sample analysis. Finally, an overview of risk assessment was discussed.

Deoxynivalenol Biomarkers in the Urine of UK Vegetarians

Deoxynivalenol (DON) is produced by Fusarium graminearum and is one of the most commonly occurring trichothecenes. Vegetarians are alleged to be a high-risk group for DON exposure due to high intakes of cereals susceptible to the growth of the mycotoxin. This study provides the levels of DON and de-epoxi Deoxynivalenol (DOM-1) in urine analysed by liquid chromatography-mass spectrometry (LC-MS) in UK vegetarians. Over two consecutive days, morning urine samples were collected from 32 vegetarians and 31 UK adult volunteers, and associated food consumption 24 h prior to the sample was recorded. Statistically significant differences between the weight of the UK adults and vegetarians (t = 3.15. df = 61, p ≤ 0.005 two-tailed) were observed. The mean levels of DON in urine for adults on day 1 was 3.05 ng free DON/mg creatinine, and on day 2 was 2.98 ng free DON/mg creatinine. Even though high mean levels were observed, most adults were within the tolerable daily intake. However, for vegetarians, the mean level of urinary DON on day 1 was 6.69 ng free DON/mg creatinine, and on day 2 was 3.42 ng free DON/mg creatinine. These levels equate to up to 32% of vegetarians exceeding recommended tolerable daily intakes (TDI) of exposure (1 µg/kg b.w./day).

Automated 3-D Printed Arrays to Evaluate Genotoxic Chemistry: E-Cigarettes and Water Samples

A novel, automated, low cost, three-dimensional (3-D) printed microfluidic array was developed to detect DNA damage from metabolites of chemicals in environmental samples. The electrochemiluminescent (ECL) detection platform incorporates layer-by-layer (LbL) assembled films of microsomal enzymes, DNA and an ECL-emitting ruthenium metallopolymer in ∼10 nm deep microwells. Liquid samples are introduced into the array, metabolized by the human enzymes, products react with DNA if possible, and DNA damage is detected by ECL with a camera. Measurements of relative DNA damage by the array assess the genotoxic potential of the samples. The array analyzes three samples simultaneously in 5 min. Measurement of cigarette and e-cigarette smoke extracts and polluted water samples was used to establish proof of concept. Potentially genotoxic reactions from e-cigarette vapor similar to smoke from conventional cigarettes were demonstrated. Untreated wastewater showed a high genotoxic potential compared to negligible values for treated wastewater from a pollution control treatment plant. Reactivity of chemicals known to produce high rates of metabolite-related DNA damage were measured, and array results for environmental samples were expressed in terms of equivalent responses from these standards to assess severity of possible DNA damage. Genotoxic assessment of wastewater samples during processing also highlighted future on-site monitoring applications.

Multi-mycotoxin analysis using dried blood spots and dried serum spots

In this study, a rapid multi-mycotoxin approach was developed for biomonitoring and quantification of 27 important mycotoxins and mycotoxin metabolites in human blood samples. HPLC-MS/MS detection was used for the analysis of dried serum spots (DSS) and dried blood spots (DBS). Detection of aflatoxins (AFB₁, AFB₂, AFG₁, AFG₂, AFM₁), trichothecenes (deoxynivalenol, DON; DON-3-glucoronic acid, DON-3-GlcA; T-2; HT-2; and HT-2-4-GlcA), fumonisin B₁ (FB₁), ochratoxins (OTA and its thermal degradation product 2'R-OTA; OTα; 10-hydroxychratoxin A, 10-OH-OTA), citrinin (CIT and its urinary metabolite dihydrocitrinone, DH-CIT), zearalenone and zearalanone (ZEN, ZAN), altenuene (ALT), alternariols (AOH; alternariol monomethyl ether, AME), enniatins (EnA, EnA₁, EnB, EnB₁) and beauvericin (Bea) was validated for two matrices, serum (DSS), and whole blood (DBS). HPLC-MS/MS analysis showed signal suppression as well as signal enhancement due to matrix effects. However, for most analytes LOQs in the lower pg/mL range and excellent recovery rate were achieved using matrix-matched calibration. Besides validation of the method, the analyte stability in DBS and DSS was also investigated. Stability is a main issue for some analytes when the dried samples are stored under common conditions at room temperature. Nevertheless, the developed method was applied to DBS samples of a German cohort (n = 50). Besides positive findings of OTA and 2'R-OTA, all samples were positive for EnB. This methodical study establishes a validated multi-mycotoxin approach for the detection of 27 mycotoxins and metabolites in dried blood/serum spots based on a fast sample preparation followed by sensitive HPLC-MS/MS analysis. Graphical Abstract ᅟ.

The Hotspot for (Global) One Health in Primary Food Production: Aflatoxin M1 in Dairy Products

One Health involves the multifaceted environment-animal-human web: nevertheless, the role of toxicological issues has yet to be fully explored in this context. Aflatoxin B1 (AFB1) contamination of feeds is a risk for the health of several farm animals, including fishes; milk is the only food of animal origin where a significant feed-food carry over may occur. The main AFB1-related compound present in milk is the hydroxy-metabolite aflatoxin M1 (AFM1). Besides contamination of raw milk, AFM1 is of concern for the whole dairy chain; AFM1 may also contaminate the milk of several other ruminants used for milk/dairy production. In a One Health perspective, milk represents a sentinel matrix for AFB1 vulnerability of the agro-food system, that is crucial in a phase when food/nutritional security becomes a global issue and climatic changes may affect agricultural productions. In the global setting, food chain exposure to long-term toxicants, such as AFM1, is a growing concern for economically developing countries, whereas global trade and climatic change makes AFM1 an emerging hot issue in economically developed countries as well. We critically review the state of the art on AFM1 risk assessment and risk management using two scenarios as case studies: a European Union country where the health system aims at ensuring a high-level protection of food chain (Italy) and the world's largest (and economically developing) producer of dairy products by volume (India). The case studies are used to provide building blocks for a global One Health framework.

Measuring biomarkers in wastewater as a new source of epidemiological information: Current state and future perspectives

The information obtained from the chemical analysis of specific human excretion products (biomarkers) in urban wastewater can be used to estimate the exposure or consumption of the population under investigation to a defined substance. A proper biomarker can provide relevant information about lifestyle habits, health and wellbeing, but its selection is not an easy task as it should fulfil several specific requirements in order to be successfully employed. This paper aims to summarize the current knowledge related to the most relevant biomarkers used so far. In addition, some potential wastewater biomarkers that could be used for future applications were evaluated. For this purpose, representative chemical classes have been chosen and grouped in four main categories: (i) those that provide estimates of lifestyle factors and substance use, (ii) those used to estimate the exposure to toxicants present in the environment and food, (iii) those that have the potential to provide information about public health and illness and (iv) those used to estimate the population size. To facilitate the evaluation of the eligibility of a compound as a biomarker, information, when available, on stability in urine and wastewater and pharmacokinetic data (i.e. metabolism and urinary excretion profile) has been reviewed. Finally, several needs and recommendations for future research are proposed.

Mycotoxin Contamination in Sugarcane Grass and Juice: First Report on Detection of Multiple Mycotoxins and Exposure Assessment for Aflatoxins B₁ and G₁ in Humans

This study was conducted to investigate the natural co-occurrence of multiple toxic fungal and bacterial metabolites in sugarcane grass and juice intended for human consumption in Upper Egypt. Quantification of the target analytes has been done using the "dilute and shoot" approach followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). A total number of 29 and 33 different metabolites were detected in 21 sugarcane grass and 40 juice samples, respectively, with a trend of concentrations being higher in grass than in juice. Among the regulated mycotoxins, only aflatoxin B₁ (AFB₁) and aflatoxin G₁ (AFG₁) were detected. The prevalence of AFB₁ was in 48% of grass samples and in 58% of juice with a maximum concentration of 30.6 μg/kg and 2.10 μg/kg, respectively. AFG₁ was detected in 10% of grass samples (7.76 μg/kg) and 18% of juice samples (34 μg/kg). Dietary exposure was assessed using a juice frequency questionnaire of adult inhabitants in Assiut City. The assessment revealed different levels of exposure to AFB₁ between males and females in winter and summer seasons. The estimated seasonal exposure ranged from 0.20 to 0.40 ng/kg b.w./day in winter and from 0.38 to 0.90 ng/kg b.w./day in summer.