Analysis of aflatoxins in nonalcoholic beer using liquid-liquid extraction and ultraperformance LC-MS/MS

Advancements in Sample Preparation Methods for the Chromatographic and Mass Spectrometric Determination of Zearalenone and Its Metabolites in Food: An Overview

Zearalenone and its metabolites are mycotoxins generated by Fusarium species while crops are growing and can typically be found in various foods, posing a risk to human health. Governments have implemented stricter regulations concerning the permissible levels of zearalenone in food products to safeguard public health. Stricter regulations on zearalenone levels in food have been implemented. However, detecting zearalenone and its metabolites remains challenging due to sample complexity and interference. Surprisingly few reviews of sample preparation methods for zearalenone in food have appeared in the past decade. In this overview, we outline the most recent developments in the sample pre-treatment technology of zearalenone and its metabolites in food samples based on chromatography-mass spectrometry methods since 2012. This review covers some prominent technologies, such as liquid-liquid extraction-based methods, solid-phase extraction-based methods, and QuEChERS (quick, easy, cheap, effective, rugged, and safe) extraction, providing valuable insights into their advantages and limitations for potential applications. The assessment of the methods discussed, along with an overview of current challenges and prospects, will guide researchers in advancing the field and ensuring safer food quality for consumers worldwide.

A highly sensitive competitive aptasensor for AFB1 detection based on an exonuclease-assisted target recycling amplification strategy

Aflatoxin B₁ (AFB₁) is a typical mycotoxin found in agricultural products, and poses a huge threat to both humans and animals. Accurate and rapid measurement of AFB₁ is essential for environmental analysis and food safety. Based on molecular docking simulation design and exonuclease-assisted target recycling amplification, we designed a competitive fluorescence aptasensor to detect AFB₁ rapidly and sensitively. According to the molecular docking simulations, a complementary strand (cDNA) was designed by searching for potential binding sites of the aptamer, which had the lowest binding energy. Magnetic beads modified with biotin-Apt were used as the capture probe, while FAM-labeled cDNA acted as the reporter probe. By using EXO I for target recycling amplification, this aptasensor was highly sensitive and selective for AFB₁. The detection limit of the suggested aptasensor under optimal conditions was 0.36 ng mL^-1 (S/N = 3) in the range of 1-1000 ng mL^-1 (R² = 0.991). The developed aptasensor was successfully used to analyze AFB₁ in oil samples.

Aflatoxin G1 exposure altered the expression of BDNF and GFAP, histopathological of brain tissue, and oxidative stress factors in male rats

Background and purpose

Aflatoxins are highly toxic compounds that can cause acute and chronic toxicity in humans and animals. This study aimed to evaluate the expression of BDNF and GFAP, histopathological changes, and oxidative stress factors in brain tissue exposed to aflatoxin G1 (AFG1) in male rats.

Experimental approach

Twenty-eight male Wistar rats were used. Animals were randomly divided into 4 groups of 7 each. The control group received 0.2 mL of corn oil and the treatment groups were exposed to AFG1 (2 mg/kg) intra-peritoneally for 15, 28, and 45 days. The tissue was used for histopathological studies, and the level of TAC, SOD, and MDA, and the expression of BDNF and GFAP genes were evaluated.

Findings/Results

Real-time PCR results showed that AFG1 increased GFAP expression and decreased BDNF expression in AFG1-treated groups compared to the control group. The tissue level of TAC and SOD over time in the groups receiving AFG1 significantly decreased and the tissue level of MDA increased compared to the control group. Histopathological results showed that AFG1 can cause cell necrosis, a reduction of the normal cells number in the hippocampal region of CA1, cerebral edema, shrinkage of nerve cells, formation of space around neuroglia, and diffusion of gliosis in the cerebral cortex after 45 days.

Conclusion and implication

AFG1, by causing pathological complications in cortical tissue, was able to affect the exacerbation of nerve tissue damage and thus pave the way for future neurological diseases.

Novel application of biodegradable chitosan in agriculture: Using green nanopesticides to control Solenopsis invicta

Botanical pesticides are biological pesticides that are environment friendly. However, their instability and short persistence limit their application. In this study, pH sensitive chitosan based rotenone (Rot) nanoparticles (CS/CMCS/Rot-NPs) were prepared using chitosan and carboxymethyl chitosan to take advantage of the acidic nature of the red fire ant midgut. Chitosan based nanoparticles showed photoprotective and slow sustained release effects on Rot and significantly increased the insecticidal activity of Rot against red fire ants. The 24-96hLC₅₀ of CS/CMCS/Rot-NPs against red fire ants was 3.28-6.84 fold that of Rot. The CS/CMCS/Rot-NPs significantly reduced the venom alkaloid content of red fire ants and their living environment and weakened their survival by increasing their survival cost in the ecological environment. Nanotechnology combined with botanical pesticides can be used as a novel, safe, effective, and ecofriendly method to control red fire ants.

Eco-friendly UPLC-MS/MS analysis of possible add-on therapy for COVID-19 in human plasma: Insights of greenness assessment

Facing the pandemic COVID-19 is of highest priority for all researchers nowadays. Recent statistics indicate that the majority of the cases are home-treated. Two drugs of interest, Guaifenesin and Bromohexine HCl, are among the add-on therapy for treatment of COVID-19 mild cases, which has raised the need for their simultaneous determination. The analysis of the two drugs of interest was described using ultra-performance liquid chromatography-tandem mass spectrometric (UPLC-MS/MS) in plasma of healthy human volunteers using tetryzoline HCl as an internal standard (IS) after liquid-liquid extraction. The applied chromatographic conditions were Kinetex C₁₈ (100 Å, 2.6 µm X 50 mm X 4.6 mm) column and a mixture of methanol: water (95: 5, v/v) as a mobile phase at flow rate 1 mL/min. The positive ionization mode was used for detecting the ions, by observing the pairs of transition m/z 199 < 125 for GUF, m/z 377 < 114 for BRM and m/z 201 < 131 for IS. The linearity range was from 50 to 1500 ng/mL for GUF and 0.5-50 µg/mL for BRM. Limit of detection (LOD) was found to be 35.16 and 0.43 ng/ml for GUF and BRM, respectively. The method was validated according to FDA guidance. The proposed method was assessed to be more eco-friendly versus the reported method using the greenness assessment tools: National Environmental Methods Index (NEMI), Assessment of Green Profile (AGP), Green Analytical Procedure Index (GAPI) and Eco-Scale. The proposed method was applied for the application of a pilot pharmacokinetic study.

Expression of cyclin D1, p21, and estrogen receptor alpha in aflatoxin G1-induced disturbance in testicular tissue of albino mice

Background and purpose

Aflatoxin (AF) is a mycotoxin produced by various strains of the Aspergillus family. AFG1 as one of the most important types is highly found in cereals and grains. AF affects sperm production or even its quality. This study was designed to test the effects of AFG1 on mice testicular tissue.

Experimental approach

Twenty-four Albino mice were divided into four groups of 6 each; a control group (0.2 mL corn oil and ethanol), three treatment groups with different periods (20 μg/kg AFG1 for 7, 15, and 35 consecutive days). All treatments were applied intraperitoneally. Biosynthesis of cyclin D1, p21, and estrogen receptor alpha (ERα) proteins was evaluated by immunohistochemistry (IHC) staining. Levels of cyclin D1, p21, and ERα mRNA were evaluated by the real-time polymerase chain reaction (RT-PCR) technique. Tubular differentiation index (TDI), reproductive index (RI), and spermiogenesis indices were also analyzed.

Findings/Results

AFG1 increased the percentage of seminiferous tubules with negative TDI, RI, and SPI compared to the control group (P < 0.05). RT-PCR and IHC analyses illustrated time-dependent enhancement in p21 expression and cyclin D1 biosynthesis in AFG1-treated groups significantly (P < 0.05). While the protein and mRNA levels of ERα were significantly (P < 0.05) decreased in a time-dependent manner.

Conclusion and implications

The chronic exposure to AFG1 reduced the expression and synthesis of ERα, increased the expression and synthesis of p21 and cyclin D1, impaired apoptosis, which in turn could impair spermatogenesis.

Rapid determination of aflatoxin B1 by an automated immunomagnetic bead purification sample pretreatment method combined with high-performance liquid chromatography

We aimed to establish an automated versatile sample preconcentration method based on the modified immunomagnetic beads, which was utilized to enrich for aflatoxin B1 from the matrices. The critical main parameters affecting the extraction efficiency, such as usage amount of immunomagnetic beads, reaction time, elution time, and blending way were investigated. Under the optimized conditions, the content of aflatoxin B1 was analyzed by high-performance liquid chromatography, the mobile phase consists of water-acetonitrile-methanol (42:18:10, v/v/v), and fluorescence detection was performed with excitation and emission wavelengths at 360 and 440 nm, respectively. Moreover, the performance of preconcentration method was compared with the conventional method based on the immunoaffinity column. The accuracy of two clean-up methods was within the error range. In addition, the stability and recyclability of the immunomagnetic beads was studied by recycling them five times. The results for the respective analysis in various samples demonstrated that the developed extraction platform provides a promising approach that is simple, rapid, sensitive, and easy to use.

Integrated in-syringe magnetic sheet solid-phase extraction and dispersive liquid-liquid microextraction for determination of aflatoxins in fresh and moldy breads

BACKGROUND

Magnetic three-dimensional graphene-based nanoadsorbents have unique characteristics such as large surface area, good thermal and chemical stability, and high adsorption capacity that make them efficient materials in sorbent-based extraction techniques. In this study, four aflatoxins (AFs) were analyzed in bread samples using magnetic three-dimensional graphene as the adsorbent phase in dispersive micro solid-phase extraction.

RESULTS AND CONCLUSIONS

In-syringe magnetic sheet solid-phase extraction based on magnetic three-dimensional graphene in tandem with dispersive liquid-liquid microextraction was used for the extraction and preconcentration of the target AFs. The effect of significant parameters of the method was investigated and the optimum conditions were determined as follows: adsorbent dosage, 20 mg; desorption/disperser solvent (methanol) volume, 700 μL; desorption solvent flow rate, 0.7 mL min^-1 ; pH, neutral; salt (NaCl) concentration, 10% (w/v); extraction solvent (chloroform) volume, 250 μL; and centrifugation rate (and time), 4000 rpm (5 min). The limits of detection and quantification were in the ranges 0.043-0.083 and 0.14-0.28 μg kg^-1 , respectively. The extraction method was followed by the HPLC technique with fluorescence detection and applied to the determination of the AFs in four different Iranian fresh and moldy bread samples. The relative recoveries were in the range 84-107% with relative standard deviations of 3.9-8.6%. © 2019 Society of Chemical Industry.

A novel HPLC flow cell integrated UV light emitting diode induced fluorescence detector as alternative for sensitive determination of aflatoxins

A novel UV light emitting diode induced fluorescence detector (LED-IF) with HPLC flow cell was designed and evaluated for determination of aflatoxins. Ray tracing method was employed to optimize the design of the optical components (such as reshaping thin lens for light source and fluorescence collection), and optical structure, and the geometry of flow cell. An ordinary UV LED with wavelength of 370 nm and radiant power of 5 mW was used as excitation light source. A photoelectric amplifier AccuOpt2000 with light sensitivity of 10^-5∼10^-4lx was utilized for fluorescence detection, instead of a photo multiplier tube (PMT). The lowest detection limit (LOD) of the LED-IF was 0.077 ppb for aflatoxin B₁ by HPLC method without derivatization. The LED-IF was then coupled with a homemade iodine derivatization device, which was connected to the HPLC column outlet for determination of aflatoxins in edible oil and peanut samples. It was found that the edible oil sample contained aflatoxin B₁ and B₂ at average level of 7.14 (n = 3) and 0.30 ng/g (n = 3), respectively; while the peanut sample contained aflatoxin B₁ and B₂ at average level of 9.22 (n = 3) and 1.36 ng/g (n = 3), respectively. The overall power consumption of the LED-IF was 1 W/12 V. The sensitivity of the LED-IF was similar to commercial fluorescence detectors, which utilized a pulse Xe lamp as excitation light source and a PMT for detection, with power consumption of 150 W.

High-performance liquid chromatographic determination of multi-mycotoxin in cereals and bean foodstuffs using interference-removal solid-phase extraction combined with optimized dispersive liquid-liquid microextraction

A novel pre-treatment was proposed for the simultaneous determination of aflatoxins, ochratoxin A and zearalenone in foodstuffs using high-performance liquid chromatography with fluorescence detection. The analytical procedure was based on a first step using a quick, easy, cheap, effective, rugged, and safe based extraction procedure, followed by salting out and purification with a C₁₈ solid-phase extraction column as interference removal clean-up. Subsequently, collected supernatant was subjected to dispersive liquid-liquid microextraction. Response surface methodology based on central composite design was employed to optimize conditions in the microextraction procedure. Under the optimum conditions, satisfactory analytical performance with recoveries ranging from 63.22 to 107.6% were achieved in different types of cereals and beans, as well as desirable precisions (0.81-8.13%). Limits of detections and quantifications for these six mycotoxins ranging from 0.03 to 13 μg/kg and 0.22 to 44 μg/kg, respectively, were obtained. Finally, the established method was successfully validated by four certified reference materials (P = 0.897 > 0.05) and applied to 79 samples from local markets.

Development of Methods for Determination of Aflatoxins

Aflatoxins can cause damage to the health of humans and animals. Several institutions around the world have established regulations to limit the levels of aflatoxins in food, and numerous analytical methods have been extensively developed for aflatoxin determination. This review covers the currently used analytical methods for the determination of aflatoxins in different food matrices, which includes sampling and sample preparation, sample pretreatment methods including extraction methods and purification methods of aflatoxin extracts, separation and determination methods. Validation for analysis of aflatoxins and safety considerations and precautions when doing the experiments are also discussed.

Simultaneous determination of four aflatoxins and ochratoxin A in ginger after inoculation with fungi by ultra-fast liquid chromatography-tandem mass spectrometry

BACKGROUND

Aflatoxins (AFs) and ochratoxin A (OTA) have been detected frequently in food, agricultural products and traditional Chinese medicines, and their presence poses serious health and economic problems worldwide. Ginger can easily be polluted with mycotoxins. In this study, ginger samples were cultivated for 15 days after inoculation with fungi and were prepared based on ultrasound-assisted solid-liquid extraction using methanol/water followed by immunoaffinity column clean-up and analysed by ultra-fast liquid chromatography-tandem mass spectrometry (UFLC-MS/MS) for AFs and OTA.

RESULTS

The limits of detection and quantification of AFs and OTA were 0.04-0.30 µg mL(-1) and 0.125-1.0 µg mL(-1) , respectively. The recoveries were 82.0-100.2%. After 15 days' cultivation, no macroscopic mildew was found in ginger. But, the content of AFB1 expressed an increasing trend in ginger, peel [less than the limit of quantification (LOQ)] to the innermost layer (51.86 µ mL(-1) ), AFB2 was only detected in the innermost layer at the level of 0.87 µ mL(-1) . A small amount (

CONCLUSION

The developed method was successfully applied to analyse five mycotoxins, and has many advantages including rapid determination and high sensitivity. Meanwhile, in practice, more attention should be paid to the safety and quality of ginger. © 2016 Society of Chemical Industry.

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Key Words

• UFLC-MS/MS
• fungi inoculation
• ginger
• mycotoxins

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MESH Headings

• Aflatoxins/analysis
• Aflatoxins/chemistry
• Aflatoxins/metabolism
• Aspergillus/metabolism
• Chromatography, High Pressure Liquid/methods
• Food Contamination/analysis
• Food Microbiology
• Food Technology/methods
• Fungi/metabolism
• Zingiber officinale/chemistry
• Zingiber officinale/metabolism
• Zingiber officinale/microbiology
• Limit of Detection
• Ochratoxins/analysis
• Ochratoxins/chemistry
• Ochratoxins/metabolism
• Tandem Mass Spectrometry/methods
• Ultrasonics/methods

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Affiliation(s)

Ying Yang School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100193, China
Jing Wen School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China
Weijun Kong Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100193, China
Qiutao Liu Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100193, China Pharmacy College, Liaoning Medical University, Jinzhou, Liaoning 121001, China
Hongli Luo School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100193, China
Jian Wang School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China
Meihua Yang Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100193, China

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Interference-free analysis of aflatoxin B1and G1in various foodstuffs using trilinear component modeling of excitation–emission matrix fluorescence data enhanced through photochemical derivatization

A novel ‘dilute-and-shoot’ strategy coupling self-weighted alternating normalized residue fitting algorithm with two-dimensional fluorescence detection enhanced by photochemical derivatization was proposed for rapid analysis of aflatoxin B₁and G₁.

High-performance liquid chromatography analysis of phenolic acid, flavonoid, and phenol contents in various natural Yemeni honeys using multi-walled carbon nanotubes as a solid-phase extraction adsorbent

A simple method has been described for simultaneous determination of phenolic acid, flavonoid, and other phenol contents in various natural honey samples collected from various regions of Yemen. Multi-walled carbon nanotubes were used as a solid-phase adsorbent for extraction of the polyphenols from honey samples. The total contents of phenolic acids, flavonoids, and phenolic components of the 12 different samples were found in the range of 363-2658, 261-1646, and 224-1355 μg/100 g of honey samples, respectively. The major phenolic acid, flavonoid, and phenolic compound in these samples were found to be 4-hydroxybenzoic acid (1410 μg/100 g), chrysin (850 μg/100 g), and cinnamic acid (1336 μg/100 g), respectively. A total of 25 compounds (10 phenolic acids, 9 flavonoids, and 6 phenols) were analyzed, and a total of 24 were detected, while only 23 compounds were determined quantitatively in the honey samples. The developed method showed potential usefulness for the analysis of honey and was used for the determination of polyphenols in honey extracts.

Cytochrome P450 2A13 is an efficient enzyme in metabolic activation of aflatoxin G1 in human bronchial epithelial cells

Cytochrome P450 2A13 (CYP2A13) is an extrahepatic enzyme that mainly expresses in human respiratory system, and it is reported to mediate the metabolic activation of aflatoxin B1. Due to the structural similarity, AFG1 is predicted to be metabolized by CYP2A13. However, the role of CYP2A13 in metabolic activation of AFG1 is unclear. In present study, human bronchial epithelial cells that stably express CYP2A13 (B-2A13) were used to conduct the effects of AFG1 on cytotoxicity, apoptosis, DNA damages, and their response protein expression. Low concentrations of AFG1 induced significant cytotoxicity and apoptosis, which was consistent with the increased expressions of pro-apoptotic proteins, such as C-PARP and C-caspase-3. In addition, AFG1 increased 8-OHdG and γH2AX in the nuclies and induced S phase arrest and DNA damage in B-2A13 cells, and the proteins related to DNA damage responses, such as ATM, ATR, Chk2, p53, BRCA1, and γH2AX, were activated. All the above effects were inhibited by nicotine (a substrate of CYP2A13) or 8-MOP (an inhibitor of CYP enzymes), confirming that CYP2A13 mediated the AFG1-induced cytotoxicity and DNA damages. Collectively, our findings first demonstrate that CYP2A13 might be an efficient enzyme in metabolic activation of AFG1 and helps provide a new insight into adverse effects of AFG1 in human respiratory system.