Development and validation of an LC-MS/MS method for the simultaneous determination of citrinin and ochratoxin a in a variety of feed and foodstuffs

Development and validation of an analytical method for determination of citrinin in red rice and red yeast rice-based food supplements by ultra-high performance liquid chromatography tandem mass spectrometry

Citrinin is a hepato-nephrotoxic mycotoxin produced by fungal species. The Monascus purpureus fungus plays a crucial role in the fermentation of red rice to produce red yeast rice-based food supplements, which represent the primary source of human exposure to citrinin. In this study, a simple and sensitive analytical method was successfully developed and validated for the citrinin determination in these products. The extraction process involved a QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) step and citrinin determination by ultra high-performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS). The proposed method provided satisfactory linearity, percentage of recovery from 82 to 104% with relative standard deviations (RSD) lower than 14%, and limits of detection and quantification of 0.07 μg/Kg and 0.24 μg/kg, respectively. Among the 14 samples analyzed, citrinin was found in two red rice samples (0.24 and 0.46 μg/kg) and in six food supplements (from 0.44 to 87 μg/kg).

Silver nanoprism-mediated colourimetric sensing probe for efficient detection of Pd(II) and Pt(II) ions in water and reuse of formed bimetallic nanoprisms

Sensitive and selective methods for detecting Pd(II) and Pt(II) ions in water are crucial for environmental monitoring and remediation. Although traditional methods for detection of Pd(II) and Pt(II) ions are accurate and sensitive, they face substantial challenges due to high costs, reliance on specialised equipment and limited field applicability, thereby presenting notable limitations. In this study, we introduce a novel colourimetric sensing probe designed specifically to identify Pd(II) and Pt(II) ions in aqueous solutions. This probe utilises the enhanced chemical stability of Ag nanoprisms achieved through Pd or Pt deposition on their surfaces. Our approach features exceptionally low limits of detection of 2.6 nM for Pd(II) and 0.3 nM for Pt(II), indicating an impressive detection range. Furthermore, the probe's ease of use, cost-effectiveness and compatibility with both naked eye and UV-Vis spectrophotometric detection make it a selective, reliable and affordable option for point-of-care analysis. Beyond its impressive sensitivity for ion detection, this methodology offers the additional benefit of enabling the on-demand synthesis of customised bimetallic catalysts. The synthesised Ag/Pd and Ag/Pt bimetallic nanoprisms demonstrate promising catalytic potential for environmental remediation. This advancement paves the way for efficient recycling and reuse of valuable Pd(II) and Pt(II) ions in various catalytic applications.

Simultaneous estimation of rutin and donepezil through RP-HPLC: implication in pharmaceutical and biological samples

Aim: A HPLC method was developed and validated for the novel combination of rutin (RN) and donepezil (DNP). Materials & methods: RN and DNP were simultaneously eluted through a C18 column (Ø 150 × 4.6 mm) with a 60:40 v/v ratio of 0.1% formic acid aqueous solution to methanol at 0.5 ml/min. Results: The purposed method was found linear, selective, reproducible, accurate and precise with percent RSD less than 2. The limit of quantification for RN and DNP was found 3.66 and 3.25 μg/ml, respectively. Conclusion: Validated as per the ICH guidelines, the developed method efficiently quantified RN and DNP co-loaded in DQAsomes (121 nm) estimating matrix effect, release profile, entrapment efficiency, loading efficiency and in vivo plasma kinetics.

Comprehensive Insights into Ochratoxin A: Occurrence, Analysis, and Control Strategies

Ochratoxin A (OTA) is a toxic mycotoxin produced by some mold species from genera Penicillium and Aspergillus. OTA has been detected in cereals, cereal-derived products, dried fruits, wine, grape juice, beer, tea, coffee, cocoa, nuts, spices, licorice, processed meat, cheese, and other foods. OTA can induce a wide range of health effects attributable to its toxicological properties, including teratogenicity, immunotoxicity, carcinogenicity, genotoxicity, neurotoxicity, and hepatotoxicity. OTA is not only toxic to humans but also harmful to livestock like cows, goats, and poultry. This is why the European Union and various countries regulate the maximum permitted levels of OTA in foods. This review intends to summarize all the main aspects concerning OTA, starting from the chemical structure and fungi that produce it, its presence in food, its toxicity, and methods of analysis, as well as control strategies, including both fungal development and methods of inactivation of the molecule. Finally, the review provides some ideas for future approaches aimed at reducing the OTA levels in foods.

Deep Eutectic Solvent-Based Dispersive Liquid-Liquid Microextraction Coupled with LC-MS/MS for the Analysis of Two Ochratoxins in Capsicum

Ochratoxins, a common class of mycotoxin in capsicum, and techniques and methods for the determination of mycotoxins in spices have been increasingly developed in recent years. An innovative and eco-friendly method of dispersive liquid-liquid microextraction (DLLME) was demonstrated in this study, based on a synthesized deep eutectic solvent (DES) combined with LC-MS/MS, for the quantification and analysis of two ochratoxins in capsicum. The DES-DLLME method parameters entail selecting the DES type (thymol:decanoic acid, molar ratio 1:1) and DES volume (100 μL). The volume of water (3 mL) and salt concentration (0 g) undergo optimization following a step-by-step approach to achieve optimal target substance extraction efficiency. The matrix effect associated with the direct detection of the target substance in capsicum was significantly reduced in this study by the addition of isotopic internal standards corresponding to the target substance. This facilitated optimal conditions wherein quantitative analysis using LC-MS/MS revealed a linear range of 0.50-250.00 µg/mL, with all two curves calibrated with internal standards showing correlation coefficients (r2) greater than 0.9995. The method's limits of detection (LODs) and limits of quantification (LOQs) fell in the ranges of 0.14-0.45 μg/kg and 0.45-1.45 μg/kg, respectively. The method's spiked recoveries ranged from 81.97 to 105.17%, indicating its sensitivity and accuracy. The environmental friendliness of the technique was assessed using two green assessment tools, AGREE and complexGAPI, and the results showed that the technique was more in line with the concept of sustainable development compared to other techniques for detecting ochratoxins in capsicum. Overall, this study provides a new approach for the determination of mycotoxins in a complex food matrix such as capsicum and other spices using DES and also contributes to the application of green analytical chemistry methods in the food industry.

Quantification and health risk assessment of ochratoxin A in dried fruit, spices, and coffee

Ochratoxin A (OTA) is a stable toxin produced by fungal strains of Aspergillus and Penicillium. It is commonly found in a variety of food products, including dried fruit, coffee, and spices, raising concerns about their safety. This study was aimed to quantify OTA levels in different food products using HPLC with fluorescence detection. The pre-treatment process was optimised by employing immunoaffinity columns with Tween 20 to effectively remove interfering substances. An analytical method was developed, validated, and applied for OTA analysis in dried fruit, spices, and coffee samples. The validation procedure included determining detection and quantification limits, linearity, precision, and accuracy, as per the criteria specified by AOAC International. The validated method was successfully applied for OTA analysis in the selected food samples. Furthermore, health risk assessment was conducted based on the average intake and body weight of the Korean population. From the results, concentrations of OTA in the samples were found to be very low and therefore concluded not to pose significant threats to consumer health.

Study of co-occurrence of mycotoxins in cocoa beans in Brazil by liquid chromatography-tandem mass spectrometry (LC-MS/MS)

In this study, 135 samples of cocoa beans collected in the Amazon and Atlantic Forest regions of Brazil were analysed to evaluate the possible co-occurrence of 34 mycotoxins. The results indicate that 42% of the cocoa samples exhibited quantifiable levels for 11 mycotoxins: aflatoxins (AFs) B1, B2 and G1; ochratoxin A; citrinin; cyclopiazonic acid; tenuazonic acid; paxilline; sterigmatocystin; zearalenone and fumonisin B2. Of the samples, 18% exhibited the co-occurrence of up to six mycotoxins. No toxins belonging to the groups of trichothecenes or ergot alkaloids were detected. Contingency analysis of the incidence of mycotoxins did not show significant differences between the two regions evaluated. Seven samples were contaminated with AFs, while only one contained ochratoxin A above 10 μg kg-1. The accuracy of the method was evaluated by proficiency testing for ochratoxin A, where satisfactory Z-scores were obtained.

Recent Insights into Sample Pretreatment Methods for Mycotoxins in Different Food Matrices: A Critical Review on Novel Materials

Mycotoxins pollution is a global concern, and can pose a serious threat to human health. People and livestock eating contaminated food will encounter acute and chronic poisoning symptoms, such as carcinogenicity, acute hepatitis, and a weakened immune system. In order to prevent or reduce the exposure of human beings and livestock to mycotoxins, it is necessary to screen mycotoxins in different foods efficiently, sensitively, and selectively. Proper sample preparation is very important for the separation, purification, and enrichment of mycotoxins from complex matrices. This review provides a comprehensive summary of mycotoxins pretreatment methods since 2017, including traditionally used methods, solid-phase extraction (SPE)-based methods, liquid-liquid extraction (LLE)-based methods, matrix solid phase dispersion (MSPD), QuEChERS, and so on. The novel materials and cutting-edge technologies are systematically and comprehensively summarized. Moreover, we discuss and compare the pros and cons of different pretreatment methods and suggest a prospect.

Recent Advances in Mycotoxin Determination in Fish Feed Ingredients

Low-cost plant-based sources used in aquaculture diets are prone to the occurrence of animal feed contaminants, which may in certain conditions affect the quality and safety of aquafeeds. Mycotoxins, a toxic group of small organic molecules produced by fungi, comprise a frequently occurring plant-based feed contaminant in aquafeeds. Mycotoxin contamination can potentially cause significant mortality, reduced productivity, and higher disease susceptibility; thus, its timely detection is crucial to the aquaculture industry. The present review summarizes the methodological advances, developed mainly during the past decade, related to mycotoxin detection in aquafeed ingredients, namely analytical, chromatographic, and immunological methodologies, as well as the use of biosensors and spectroscopic methods which are becoming more prevalent. Rapid and accurate mycotoxin detection is and will continue to be crucial to the food industry, animal production, and the environment, resulting in further improvements and developments in mycotoxin detection techniques.

Multi-mycotoxin determination in plant-based meat alternatives and exposure assessment

The aim of this study was to fill in the gap regarding the occurrence of mycotoxins in plant-based meat alternatives. Hence, a multi-mycotoxin method (aflatoxins, ochratoxin A, fumonisins, zearalenone, and mycotoxins from the Alternaria alternata genera) was developed followed by an exposure assessment for the Italian consumers' exposure to mycotoxins. A total of 13 meat alternatives samples based on soy, pea, chickpea, lupin, and seitan were analysed. With the exception of seitan, all of the remaining samples were contaminated with one mycotoxin or mixtures of up to seven mycotoxins. The level of contamination was as low as 0.2 μg/kg alternariol methyl ether and as high as 66.9 μg/kg fumonisin B1. To analyse the exposure to mycotoxins due to plant-based meat alternatives consumption we used the consumption meat data from the Food and Agriculture Organization for Italian adult consumers and simulated a full replacement of meat with plant-based meat alternatives. Based on our model, consumption of plant-based meat alternatives led to a non-tolerable exposure to alternariol (hazard index (HI) > 1) in pea-based burger and soy + wheat-based steak, while samples contaminated with aflatoxins, respectively ochratoxin A, indicated a health concern related to liver and renal cancer (margin of exposure (MOE) < 10,000). This is the first study that presents the co-occurrence of mycotoxins in multiple plant-based meat alternatives. Moreover, these results indicate that there is a need for policymakers to consider the regulation of mycotoxins in plant-based meat alternatives in order to ensure consumers' safety.

Meireles M, Ibáñez E. Synergic effect of natural deep eutectic solvent and high-intensity ultrasound on obtaining a ready-to-use genipin extract: Crosslinking and anti-neurodegenerative properties

In this paper, genipin, an important natural crosslinker and anti-neurodegenerative compound, was extracted from unripe Genipa americana L., combining high-intensity ultrasound (HIUS) and natural deep eutectic solvents (NADESs). The extraction process conditions were evaluated step-by-step to reach the best genipin recovery. The obtained ready-to-use genipin-NADES extract was examined regarding its crosslinking properties and anti-neurodegenerative capacity. For the condictions tested, the highest genipin recovery was obtained using 40 % water and 60 % betaine:lactic acid NADES in molar ratio 1:3 (n/n) as the solvent, a solvent:feed ratio of 19 (w/w), and HIUS acoustic power of 14 ± 1 W. The HIUS-assisted extraction using NADES as solvent showed to be a promising and efficient green extraction technique to obtain genipin. The ready-to-use genipin-NADES extract presented crosslinking capacity and anticholinergic activity. These results indicate that genipin-NADES extract can be directly applied in hydrogels for drug delivery, films, tissue engineering, and others. Moreover, it can be used in food, supplements, and medicine to enhance their neuroprotective effect.

Detoxification of the Mycotoxin Citrinin by a Manganese Peroxidase from Moniliophthora&nbsp;roreri

Citrinin (CIT) is a mycotoxin found in foods and feeds and most commonly discovered in red yeast rice, a food additive made from ordinary rice by fermentation with Monascus. Currently, no enzyme is known to be able to degrade CIT effectively. In this study, it was discovered that manganese peroxidase (MrMnP) from Moniliophthora roreri could degrade CIT. The degradation appeared to be fulfilled by a combination of direct and indirect actions of the MrMnP with the CIT. Pure CIT, at a final concentration of 10 mg/L, was completely degraded by MrMnP within 72 h. One degradation product was identified to be dihydrocitrinone. The toxicity of the CIT-degradation product decreased, as monitored by the increased survival rate of the Caco-2 cells incubated with MrMnP-treated CIT. In addition, MrMnP could degrade CIT (with a starting concentration of up to 4.6 mg/L) completely contaminated in red yeast rice. MrMnP serves as an excellent candidate enzyme for CIT detoxification.

Ochratoxin A and Citrinin Differentially Modulate Bovine Mammary Epithelial Cell Permeability and Innate Immune Function

Frequent detection of mycotoxins ochratoxin A (OTA) and citrinin (CIT) in ruminant feed and feedstuff can be a potential threat to feed safety, animal performance and health. Ineffective biodegradation of these mycotoxins by rumen microflora following ingestion of contaminated feeds can lead to their circulatory transport to tissues such as mammary gland as the result of their biodistribution throughout the body. The bovine mammary epithelium plays a pivotal role in maintaining milk yield and composition and contributes to innate immune defense of the udder. The present study is the first to investigate individual effects of OTA and CIT on barrier and innate immune functions of the bovine mammary epithelium using a bovine mammary epithelial cell line (MAC-T). Results indicated that OTA and CIT exposure for 48 h significantly decreased cell viability in a concentration-dependent manner (p < 0.05). A decrease in transepithelial electrical resistance and increase in paracellular flux of FITC-40 kDa dextran was significantly induced by OTA treatment (p < 0.05), but not by CIT after 48 h exposure. qPCR was performed for assessment of expression of tight-junction proteins, Toll-like receptor 4 (TLR4) and cytokines after 4, 24 and 48 h of exposure. Both OTA and CIT markedly downregulated expression of claudin 3 and occludin (p < 0.05), whereas CIT did not affect zonula occludens-1 expression. Expression of TLR4 was significantly upregulated by OTA (p < 0.001) but downregulated by CIT (p < 0.05) at 48 h. Expression of IL-6, TNF-a and TGF-β was significantly upregulated by OTA (p < 0.05), whereas IL-6 and TGF-β expression was downregulated by CIT (p < 0.01). These results suggest that OTA and CIT could potentially differentially modulate barrier and innate immune functions of mammary epithelium. The present study not only throws light on the individual toxicity of each mycotoxin on bovine mammary epithelium but also lays the foundation for future studies on the combined effects of the two mycotoxins.

A Novel Fluorescent Aptasensor Based on Real-Time Fluorescence and Strand Displacement Amplification for the Detection of Ochratoxin A

It is urgently necessary to develop convenient, reliable, ultrasensitive and specific methods of ochratoxin A determination in food safety owing to its high toxicity. In the present study, an ultrasensitive and labeled-free fluorescent aptamer sensor combining real-time fluorescence with strand displacement amplification (SDA) was fabricated for the determination of OTA. In the presence of OTA, the OTA–aptamer combines with OTA, thus opening hairpins. Then, SDA primers specifically bind to the hairpin stem, which is used for subsequent amplification as a template. SDA amplification is initiated under the action of Bst DNA polymerase and nicking endonuclease. The amplified products (ssDNA) are dyed with SYBR Green II and detected with real-time fluorescence. The method has good linearity in the range of 0.01–50 ng mL⁻¹, with the lowest limit of detection of 0.01 ng mL⁻¹. Additionally, the fluorescent aptamer sensor shows outstanding specificity and reproducibility. Furthermore, the sensor shows excellent analytical performance in the artificial labeled detection of wheat and oat samples, with a recovery rate of 96.1~100%. The results suggest that the developed sensor has a promising potential application for the ultrasensitive detection of contaminants in food.

Toolbox for the Extraction and Quantification of Ochratoxin A and Ochratoxin Alpha Applicable for Different Pig and Poultry Matrices

Ochratoxin A (OTA) is one of the major mycotoxins causing severe effects on the health of humans and animals. Ochratoxin alpha (OTα) is a metabolite of OTA, which is produced through microbial or enzymatic hydrolysis, and one of the preferred routes of OTA detoxification. The methods described here are applicable for the extraction and quantification of OTA and OTα in several pig and poultry matrices such as feed, feces/excreta, urine, plasma, dried blood spots, and tissue samples such as liver, kidney, muscle, skin, and fat. The samples are homogenized and extracted. Extraction is either based on a stepwise extraction using ethyl acetate/sodium hydrogencarbonate/ethyl acetate or an acetonitrile/water mixture. Quantitative analysis is based on reversed-phase liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). Method validation was successfully performed and the linearity, limit of quantification, accuracy, precision as well as the stability of the samples, were evaluated. The analyte recovery of the spiked samples was between 80 and 120% (80–150% for spiked concentrations ≤ 1 ng/g or ng/mL) and the relative standard deviation was ≤ 15%. Therefore, we provide a toolbox for the extraction and quantification of OTA and OTα in all relevant pig and poultry matrices.

Overview of Recent Liquid Chromatography Mass Spectrometry-Based Methods for Natural Toxins Detection in Food Products

Natural toxins include a wide range of toxic metabolites also occurring in food and products, thus representing a risk for consumer health. In the last few decades, several robust and sensitive analytical methods able to determine their occurrence in food have been developed. Liquid chromatography mass spectrometry is the most powerful tool for the simultaneous detection of these toxins due to its advantages in terms of sensitivity and selectivity. A comprehensive review on the most relevant papers on methods based on liquid chromatography mass spectrometry for the analysis of mycotoxins, alkaloids, marine toxins, glycoalkaloids, cyanogenic glycosides and furocoumarins in food is reported herein. Specifically, a literature search from 2011 to 2021 was carried out, selecting a total of 96 papers. Different approaches to sample preparation, chromatographic separation and detection mode are discussed. Particular attention is given to the analytical performance characteristics obtained in the validation process and the relevant application to real samples.

A CdSe@CdS quantum dots based electrochemiluminescence aptasensor for sensitive detection of ochratoxin A

In this work, a CdSe@CdS quantum dots (QDs) based label-free electrochemiluminescence (ECL) aptasensor was developed for the specific and sensitive detection of ochratoxin A (OTA). Chitosan (CHI) could immobilize abundant QDs on the surface of an Au electrode as the luminescent nanomaterials. Glutaraldehyde was used as the crosslinking agent for coupling a large number of OTA aptamers. Thanks to the excellent stability, good biocompatibility, and strong ECL intensity of CdSe@CdS QDs, as well as the quick reactions of the generated SO₄•- in the electrolyte, strong ECL signals were measured. Because of the specific recognition of aptamer toward OTA, the reduced ECL signals caused by OTA in the samples were recorded for quantify the content of OTA. After optimizing a series of crucial conditions, the ECL aptasensor displayed superior sensitivity for OTA with a detection limit of 0.89 ng/mL and a wide linear concentration range of 1-100 ng/mL. The practicability and viability were verified through the rapid and facile analysis of OTA in real Lily and Rhubarb samples with recovery rates (n = 3) of 98.1-105.6% and 97.3-101.5%, respectively. The newly-developed QDs-based ECL aptasensor provided a new universal analytical tool for more mycotoxins in safety assessment of foods and feeds, environmental monitoring, and clinical diagnostics.

Electrochemiluminescence Immunosensor Based on Nanobody and Au/CaCO3 Synthesized Using Waste Eggshells for Ultrasensitive Detection of Ochratoxin A

A novel ultrasensitive electrochemiluminescence (ECL) immunoassay based on Au/CaCO₃ was proposed for detecting ochratoxin A (OTA) in coffee. Au/CaCO₃ nanocomposites synthesized using waste eggshells as the template with a large surface area and excellent electrochemical properties were applied for immobilizing a large amount of Ru(bpy)₃ ²⁺ and conjugating a high-affinity nanobody (prepared by the phage display technique). Coupling of the Au/CaCO₃ nanocomposites and nanobody technologies provided an ultrasensitive and highly selective ECL immunosensor for OTA detection in the range of 10 pg/mL-100 ng/mL with a low detection limit of 5.7 pg/mL. Moreover, the as-prepared ECL immunosensor showed excellent performance and high stability. Finally, the proposed ECL sensor was applied to analyze OTA in coffee samples, confirming the desirable accuracy and practical applicability potential. Overall, this work presents a new nanomaterial for fabricating the sensing interface of immunosensors by harnessing natural waste as the source and a method for detecting toxic OTA in foods.

Determination and Comprehensive Risk Assessment of Dietary Exposure to Ochratoxin A on Fermented Teas

A specialized method for ochratoxin A (OTA) determination on fermented teas was developed and validated using ultraperformance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). Methodology results showed that recovery, relative standard deviation, accuracy, and precision were qualified. The limits of detection and quantification were 0.32 and 0.96 μg/kg, respectively. Two of 158 collected samples were screened for OTA contamination. Comprehensive risk assessment based on OTA contaminations of this study and other peer-reviewed publications was performed. The highest hazard quotient (HQ) value (8.86 × 10^-2) and the highest 1/MoE value (8.61 × 10^-5) in probabilistic assessment were equally below the recommended non-neoplastic and neoplastic thresholds, indicating no health risks. However, the HQ and 1/MoE values of the 95th percentiles in 20-39 and ≥50 years of age were close to thresholds of 1.0 and 1.0 × 10^-4, respectively. Under the extreme case, there were only a few scenarios (e.g., 40-49 years of age) of HQ values below the non-neoplastic threshold, but the 1/MoE value of each group exceeded the neoplastic threshold. This is the first extensive risk assessment on OTA from fermented teas worldwide, but the sample size is still limited, and a large number of samples is encouraged in a future study for a more accurate assessment.

Assessment of Citrinin in Spices and Infant Cereals Using Immunoaffinity Column Clean-Up with HPLC-Fluorescence Detection

Historically, the analysis of citrinin has mainly been performed on cereals such as red yeast rice; however, in recent years, more complex and abnormal commodities such as spices and infant foods are becoming more widely assessed. The aim of this study was to develop and validate clean-up methods for spices and cereal-based infant foods using a citrinin immunoaffinity column before HPLC analysis with fluorescence detection. Each method developed was validated with a representative matrix, spiked at various citrinin concentrations, based around European Union (EU) regulations set for ochratoxin A (OTA), with recoveries >80% and % RSD < 9% in all cases. The limit of detection (LOD) and the limit of quantification (LOQ) were established at 1 and 3 µg/kg for spices and 0.1 and 0.25 µg/kg for infant cereals, respectively. These methods were then tested across a variety of spices and infant food products to establish efficacy with high recoveries >75% and % RSD < 5% across all matrices assessed. Therefore, these methods proved suitable for providing effective clean-up of spices and infant cereals, enabling reliable quantification of citrinin detected. Samples such as nutmeg and infant multigrain porridge had higher levels of citrinin contamination than anticipated, indicating that citrinin could be a concern for public health. This highlighted the need for close monitoring of citrinin contamination in these commodities, which may become regulated in the future.

Rapid Detection and Quantification of Patulin and Citrinin Contamination in Fruits

Patulin (PAT) and citrinin (CTN) are the most common mycotoxins produced by Penicillium and Aspergillus species and are often associated with fruits and fruit by-products. Hence, simple and reliable methods for monitoring these toxins in foodstuffs are required for regular quality assessment. In this study, we aimed to establish a cost-effective method for detection and quantification of PAT and CTN in pome fruits, such as apples and pears, using high-performance liquid chromatography (HPLC) coupled with spectroscopic detectors without the need for any clean-up steps. The method showed good performance in the analysis of these mycotoxins in apple and pear fruit samples with recovery ranges of 55–97% for PAT and 84–101% for CTN, respectively. The limits of detection (LOD) of PAT and CTN in fruits were 0.006 µg/g and 0.001 µg/g, while their limits of quantification (LOQ) were 0.018 µg/g and 0.003 µg/g, respectively. The present findings indicate that the newly developed HPLC method provides rapid and accurate detection of PAT and CTN in fruits.

Development and validation of an extraction method using liquid chromatography-tandem mass spectrometry to determine patulin in apple juice

Patulin (PAT) is a potent mycotoxin commonly found in apples and apple-based products such as juice, thus affecting global food safety. Therefore, development of fast and simple analytical methods to effectively control its contamination is of great importance. This study developed and validated a technique for the analysis of PAT in samples of industrialized apple juice based on liquid-liquid extraction and using acetonitrile as the extraction solvent. Detection via mass spectrometry was performed after Atmospheric Pressure Chemical Ionization (APCI). Mean recoveries of 97.5, 92.49 and 96.92% were reached for 4, 8 and 20 μg/L of PAT, respectively. The analyte was monitored with an APCI source in negative ion mode to identify its fragments. The 24 analyzed samples presented PAT levels below the limit of quantification. It may be concluded that the method fulfilled all of the validation criteria, thus being appropriate for routine surveillance of PAT in apple juice.

Multi-residue analysis of 20 mycotoxins including major metabolites and emerging mycotoxins in freshwater using UHPLC-MS/MS and application to freshwater ponds in flanders, Belgium

Mycotoxins are known for their negative impact on human and animal health as they frequently contaminate food and feed products from crop origin that are consumed by humans and animals. Furthermore, mycotoxins can leach out of plant tissue, to be transported through runoff water into nearby ponds where they can exert negative effects on aquatic organisms, such as fish, amphibians and zooplankton. The overall goal of this study was to develop a SPE-UHPLC-MS/MS method for the detection and quantification of multiple mycotoxins in amphibian breeding ponds. The method was validated and yielded acceptable within-run and between-run apparent recoveries and precision, as well as good linearity. Matrix effects (i.e. 75.7-109.6%, ≤ 17.8% RSD) were evaluated using water from 20 different ponds in Flanders, Belgium. By incorporating internal standards, overall results improved and adequate precision values (i.e. ≤ 15%) were obtained according to the EMA guideline. Additionally, extraction recovery (n = 3) was evaluated, yielding good results for all mycotoxins (i.e. 75.3-109.1%, ≤15% RSD), except for AME (i.e. 6.7 ± 0.7%), which implied the need for a matrix-matched calibration curve. Detection sensitivity was in the low nanograms per liter range. Storage stability experiments indicated that sample storage at 4 °C in amber glass bottles and analysis performed within 96 h after sampling was sufficient to avoid loss by degradation for all compounds, excluding β-ZAL and β-ZEL, for which analysis within 24 h is more indicated. The method was successfully applied to water samples originating from 18 amphibian breeding ponds situated across Flanders. Overall, enniatins B, B1 and A1 were most commonly detected at maximum concentrations of 6.9, 3.3 and 2.6 ng L^-1, respectively, followed by detection of beauvericin (1.1 ng L^-1 and < 1 ng L^-1), alternariol monomethyl ether (< 10 ng L^-1), HT2-toxin (< 40 ng L^-1), zearalenone (< 25 ng L^-1) and α-zearalanol (< 10 ng L^-1). We believe that this method will boost further research into the dynamics and ecotoxicological impact of mycotoxins in aquatic environments.

Citrinin Determination in Food and Food Supplements by LC-MS/MS: Development and Use of Reference Materials in an International Collaborative Study

The development of incurred reference materials containing citrinin (CIT) and their successful application in a method validation study (MVS) in order to harmonize CIT determination in food and food supplements are demonstrated. CIT-contaminated materials made of red yeast rice (RYR), wheat flour, and Ginkgo biloba leaves (GBL), as well as food supplements made of red yeast rice (FS-RYR) and Ginkgo biloba leaves (FS-GBL), were manufactured in-house via fungal cultivation on collected raw materials. The homogeneity and stability from randomly selected containers were verified according to the ISO 13528. CIT was found to be homogenously distributed and stable in all contaminated materials, with no significant degradation during the timescale of the MVS when storage was performed up to +4 °C. Next, an MVS was organized with eighteen international laboratories using the provided standard operating procedure and 12 test materials, including three RYRs (blank, <50 µg/kg, <2000 µg/kg), two wheat flours (blank, <50 µg/kg), two GBL powders (blank, <50 µg/kg), three FS-RYRs (blank, <50 µg/kg, <2000 µg/kg), and two FS-GBLs (blank, <50 µg/kg). The results of seven CIT-incurred materials showed acceptable within-laboratory precision (RSDr) varying from 6.4% to 14.6% and between-laboratory precision (RSDR) varying from 10.2% to 37.3%. Evidenced by HorRat values < 2.0, the results of the collaborative trial demonstrated that the applied analytical method could be standardized. Furthermore, the appropriateness of producing CIT reference materials is an important step towards food and feed quality control systems and the organization of proficiency tests.

Mycotoxins in food: a review on liquid chromatographic methods coupled to mass spectrometry and their experimental designs

The development of a multi-mycotoxins method using LC-MS/MS is necessary and it is clear that the development of such method involves many compromises in the choice of the different parameters. This review summarizes applications using conventional experimental designs and some recent studies using response surface methodology (RSM) as a mathematical modeling tool for the optimization of extraction procedures. The authors also discuss pros and cons of the different procedures. To our knowledge, it is the first review on experimental design for the development of multi-mycotoxin methods. This review could be useful in the development and optimization of LC-MS/MS methods with the aim of describing experimental design and variables (factors) that are likely to affect sensitivity and specificity.

Dietary exposure assessment and risk characterization of citrinin and ochratoxin A in Belgium

Exposure to mycotoxins is a worldwide problem. To ensure public health, it is imperative to characterize the risks related to these toxins. The present study aims to conduct a dietary exposure assessment of citrinin (CIT) and ochratoxin A (OTA) in the Belgian population using consumption data of a variety of foodstuffs. A total of 367 food samples from different food categories were collected in Belgian supermarkets and analysed for CIT and OTA using a validated liquid chromatography-tandem mass spectrometry method. Daily CIT and OTA exposure to the Belgian population was calculated based on the analytical results and food consumption data in three age categories (3-9, 10-17 and 18-64 years), obtained from a national food consumption survey. Furthermore, a risk characterization was performed for CIT, in which no intake values exceeded the tolerable daily intake (TDI) of 200 ng kg^-1 bw day^-1, indicating no health risk. However, a CIT intake level of 187 ng kg^-1 bw day^-1 was detected for children in the age category of 3-9 years in the worst case scenario for rice, indicating that rice consumption could contain a potential health hazard for young children. For OTA, a potential health risk was detected in several food categories (biscuits, croissants, rice, flour, meat imitates, herbs and spices) in the higher percentiles (P99) or at maximum found concentrations when calculating the margin of exposure (MoE) for neoplastic effects. An attempt to perform a cumulative health risk assessment for both toxins was done. Although a high number of uncertainties is involved, combined margin of exposure (MoET) values indicated a potential health risk related to the combined exposure to CIT and OTA. For the first time, our study demonstrated the potential health risks of CIT and OTA after individual and combined exposure, in particular related to rice consumption. Moreover, further research is recommended concerning multiple mycotoxin exposure in young children.

A label-free, direct solid-phase fluorimetric analysis of ochratoxin A in agricultural products with monoclonal antibody-immobilized monolith

We established a method for directly measuring mycotoxin ochratoxin A (OTA) in foods by solid-phase fluorescence of monolith-immobilized antibodies. The antibody was introduced onto only one side of an 8 mm-diameter, 3 mm-thick monolith via covalently immobilized protein G. 4 μg (2.7 × 10^-11 mol) of antibody was immobilized per one monolith. A maximum of 10 μg (2.4 × 10^-11 mol) OTA adsorbed to the activated side of each monolith. The amount of OTA adsorbed and the fluorescence intensity showed good linearity in the range of 0.5-3 ng OTA. Loading the sample solution onto the non-antibody side on the monolith blocked the hydrophobic fluorescent matrices from reaching the immobilized surface of the antibody. The proposed method was able to detect 1 ng OTA/g in solid samples with complex matrices. Mean recoveries obtained at spiked concentration of 3 ng g^-1 OTA/g were 78-90% with relative standard deviations of <7.9%.

A Study of Carry-Over and Histopathological Effects after Chronic Dietary Intake of Citrinin in Pigs, Broiler Chickens and Laying Hens

Citrinin (CIT) is a polyketide mycotoxin occurring in a variety of food and feedstuff, among which cereal grains are the most important contaminated source. Pigs and poultry are important livestock animals frequently exposed to mycotoxins, including CIT. Concerns are rising related to the toxic, and especially the potential nephrotoxic, properties of CIT. The purpose of this study was to clarify the histopathological effects on kidneys, liver, jejunum and duodenum of pigs, broiler chickens and laying hens receiving CIT contaminated feed. During 3 weeks, pigs (n = 16) were exposed to feed containing 1 mg CIT/kg feed or to control feed (n = 4), while 2 groups of broiler chickens and laying hens (n = 8 per group) received 0.1 mg CIT/kg feed (lower dose group) and 3 or 3.5 mg CIT/kg feed (higher dose group), respectively, or control feed (n = 4). CIT concentrations were quantified in plasma, kidneys, liver, muscle and eggs using a validated ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method. Kidneys, liver, duodenum and jejunum were evaluated histologically using light microscopy, while the kidneys were further examined using transmission electron microscopy (TEM). Histopathology did not reveal major abnormalities at the given contamination levels. However, a significant increase of swollen and degenerated mitochondria in renal cortical cells from all test groups were observed (p < 0.05). These observations could be related to oxidative stress, which is the major mechanism of CIT toxicity. Residues of CIT were detected in all collected tissues, except for muscle and egg white from layers in the lowest dose group, and egg white from layers in the highest dose group. CIT concentrations in plasma ranged between 0.1 (laying hens in lower dose group) and 20.8 ng/mL (pigs). In tissues, CIT concentrations ranged from 0.6 (muscle) to 20.3 µg/kg (liver) in pigs, while concentrations in chickens ranged from 0.1 (muscle) to 70.2 µg/kg (liver). Carry-over ratios from feed to edible tissues were between 0.1 and 2% in pigs, and between 0.1 and 6.9% in chickens, suggesting a low contribution of pig and poultry tissue-derived products towards the total dietary CIT intake for humans.

Development and validation of a liquid chromatography tandem mass spectrometry multi-method for the determination of 41 free and modified mycotoxins in beer

A fast high performance liquid chromatography tandem mass spectrometry multi-method based on an ACN-precipitation extraction was developed for the analysis of 41 (modified) mycotoxins in beer. Validation according to the performance criteria defined by the European Commission (EC) in Commission Decision no. 657/2002 revealed good linearity (R² > 0.99), repeatability (RSDr < 15%), reproducibility (RSDR < 15%), and recovery (79-100%). Limits of quantification ranging from 0.04 to 75 µg/L were obtained. Matrix effects varied from -67 to +319% and were compensated for using standard addition. In total, 87 beer samples, produced worldwide, were analyzed for the presence of mycotoxins with a focus on modified mycotoxins, whereof 76% of the samples were contaminated with at least one mycotoxin. The most prevalent mycotoxins were deoxynivalenol-3-glucoside (63%), HT-2 toxin (15%), and tenuazonic acid (13%). Exposure estimates of deoxynivalenol and its metabolites for German beer revealed no significant contribution to intake of deoxynivalenol.

Recent advances in analytical methods for the determination of citrinin in food matrices

Citrinin is a toxic small organic molecule produced as a secondary metabolite by fungi types Penicillium, Monascus and Aspergillus and is known to contaminate various food commodities during postharvest stages of food production. During the last 10 years, most reported methods for citrinin analysis employed enzyme-linked immunosorbent assays or high-performance liquid chromatography. Over this same time period, liquid extraction, solid-phase extraction, dispersive liquid-liquid microextraction and QuEChERS were the most cited sample preparation and clean-up methods. In this review the advantages and disadvantages of the various sample preparation, separation and detection methods for citrinin analysis over the last decade are evaluated. Furthermore, current trends, emerging technologies and the future prospects of these methods are discussed.

Comprehensive toxicokinetic analysis reveals major interspecies differences in absorption, distribution and elimination of citrinin in pigs and broiler chickens

A comprehensive toxicokinetic analysis of citrinin (CIT) revealed interspecies differences for all toxicokinetic parameters and in absolute oral bioavailability. Oral bioavailability for CIT was complete for broilers (113-131%), while ranging from 37 to 44% in pigs. CIT was more rapidly absorbed in pigs (T_max = 0.92 h) compared to broiler chickens (T_max = 7.33 h). The elimination of CIT was slower in pigs (T_1/2el = 26.81 h after intravenous (IV) administration) compared to chickens (T_1/2el = 1.97 h after IV administration), due to the striking difference in clearance (Cl_iv=9.87 mL/h/kg for pigs versus Cl_iv = 863.09 mL/h/kg for broilers). Also, the volume of distribution differed significantly between pigs (Vd = 0.30 L/kg after IV administration) and chickens (Vd = 2.46 L/kg after IV administration). However, plasma protein binding did not differ statistically significant (91-98%). It is imperative to further investigate biotransformation and elimination pathways in different species, including humans.

Developments in mycotoxin analysis: an update for 2018-19

This review summarises developments on the analysis of various matrices for mycotoxins that have been published in the period from mid-2018 to mid-2019. Analytical methods to determine aflatoxins, Alternaria toxins, ergot alkaloids, fumonisins, ochratoxins, patulin, trichothecenes, and zearalenone are covered in individual sections. Advances in sampling strategies are also discussed in a dedicated section. In addition, developments in multi-mycotoxin methods – including comprehensive mass spectrometric-based methods as well as simple immunoassays – are also reviewed. This critical review aims to briefly present the most important recent developments and trends in mycotoxin determination as well as to address limitations of the presented methodologies.

A green and simple procedure based on deep eutectic solvents for the extraction of phthalates from beverages

In this work, a green, inexpensive, simple and fast deep eutectic solvent (DES)-based dispersive liquid-liquid microextraction was evaluated, for the first time, for the extraction of phthalates (i.e. benzylbutyl phthalate, diisobutyl phthalate, diisopentyl phthalate, di-n-pentyl phthalate, di-(2-ethylhexyl) phthalate, di-n-octyl phthalate, diisononyl phthalate, diisodecyl phthalate) from different beverages. Separation and determination were achieved by high performance liquid chromatography-diode-array detection while confirmation was carried out by tandem mass spectrometry. The main factors affecting the extraction such as type and volume of DES and emulsifier, pH and ionic strength, were optimised. Choline chloride:phenol-based DES showed the best results. The methodology was validated for tea, apple-based beverage and pineapple juice. Recovery values ranged from 84 to 120% with relative standard deviation values lower than 11%. Limits of detection of the method were in the range 5.1-14.2 µg L^-1 for tea, 5.3-17.8 µg L^-1 for apple beverages and 5.9-15.6 µg L^-1 for pineapple juices.

Nanobody-based fluorescence resonance energy transfer immunoassay for noncompetitive and simultaneous detection of ochratoxin a and ochratoxin B

A noncompetitive and homogeneous fluorescence resonance energy transfer (FRET) immunoassay was developed using a nanobody (Nb) for highly sensitive and simultaneous detection of ochratoxin A (OTA) and ochratoxin B (OTB). The promoted intrinsic fluorescence (λ_ex: 280 nm) of tryptophan residues (donor) in Nb can excite the fluorescence of OTA and OTB (acceptor) for detection (λ_em: 430 nm). Using optimal conditions, the limits of detection of the Nb-based FRET immunoassay were 0.06 and 0.12 ng/mL for OTA and OTB, respectively. Minimal cross reactivity was detected for several analogues of OTA and OTB as well as nonspecific proteins and antibodies. Acceptable accuracy and precision were obtained in the spike and recovery study, and the results correlated well with those by HPLC. These results demonstrated that the developed method could be a useful tool for noncompetitive, homogeneous, and simultaneous detection of OTA and OTB as well as other environmental analytes with similar fluorescence properties.

Nephrotoxicity instead of immunotoxicity of OTA is induced through DNMT1-dependent activation of JAK2/STAT3 signaling pathway by targeting SOCS3

Ochratoxin A (OTA) is reported to induce nephrotoxicity and immunotoxicity in animals and humans. However, the underlying mechanism and the effects of OTA on DNA damage have not been reported until now. The present study aims to investigate OTA-induced cytotoxicity and DNA damage and the underlying mechanism in PK15 cells and PAMs. The results showed that OTA at 2.0-8.0 µg/mL for 24 h induced cytotoxicity and DNA damage in PK15 cells and PAMs as demonstrated by decreasing cell viabilities and mRNA levels of DNA repair genes (OGG1, NEIL1 and NEIL3), increasing LDH release, Annexin V staining cells, apoptotic nuclei and the accumulation of γ-H2AX foci. OTA at 2.0-8.0 µg/mL increased DNMT1 and SOCS3 mRNA expressions about 2-4 fold in PK15 cells or 1.3-2 fold in PAMs. OTA at 2.0-8.0 µg/mL increased DNMT1, SOCS3, JAK2 and STAT3 protein expressions in PK15 cells or PAMs. DNMT inhibitor (5-Aza-2-dc), promoted SOCS3 expression, inhibited JAK2 and STAT3 expression, alleviated cytotoxicity, apoptosis and DNA damage induced by OTA at 4.0 µg/mL in PK15 cells. While, in PAMs, 5-Aza-2-dc had no effects on SOCS3 expression induced by OTA at 4.0 µg/mL, but inhibited JAK2 and STAT3 expression, and alleviated cytotoxicity, apoptosis and DNA damage induced by OTA. JAK inhibitor (AG490) or STAT3-siRNA alleviated OTA-induced cytotoxicity and DNA damage in PK15 cells or PAMs. Taken together, nephrotoxicity instead of immunotoxicity of OTA is induced by targeting SOCS3 through DNMT1-mediated JAK2/STAT3 signaling pathway. These results provide a scientific and new explanation of the underlying mechanism of OTA-induced nephrotoxicity and immunotoxicity.

QuEChERS - Fundamentals, relevant improvements, applications and future trends

The Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) method is a simple and straightforward extraction technique involving an initial partitioning followed by an extract clean-up using dispersive solid-phase extraction (d-SPE). Originally, the QuEChERS approach was developed for recovering pesticide residues from fruits and vegetables, but rapidly gained popularity in the comprehensive isolation of analytes from different matrices. According to PubMed, since its development in 2003 up to November 2018, about 1360 papers have been published reporting QuEChERS as extraction method. Several papers have reported different improvements and modifications to the original QuEChERS protocol to ensure more efficient extractions of pH-dependent analytes and to minimize the degradation of labile analytes. This analytical approach shows several advantages over traditional extraction techniques, requiring low sample and solvent volumes, as well as less time for sample preparation. Furthermore, most of the published studies show that the QuEChERS protocol provides higher recovery rate and a better analytical performance than conventional extraction procedures. This review proposes an updated overview of the most recent developments and applications of QuEChERS beyond its original application to pesticides, mycotoxins, veterinary drugs and pharmaceuticals, forensic analysis, drugs of abuse and environmental contaminants. Their pros and cons will be discussed, considering the factors influencing the extraction efficiency. Whenever possible, the performance of the QuEChERS is compared to other extraction approaches. In addition to the evolution of this technique, changes and improvements to the original method are discussed.