Potential carcinogenic heterocyclic aromatic amines (HAAs) in foodstuffs: Formation, extraction, analytical methods, and mitigation strategies.

During the heat treatment of proteinaceous food, heterocyclic aromatic amines (HAAs), a kind of strong mutagens/carcinogens are formed. HAAs can be classified into two major groups based on the heating temperature, which are thermic HAAs generally formed in 150 to 300 °C and pyrolytic HAAs produced above 300 °C. This review focuses on the formation mechanisms of HAAs and identifies different mechanisms of the formation of HAAs in foodstuffs. Moreover, an overview of the available extraction, purification methods, and instrumental analytical methods in the last two decades is shown to determine the HAAs in various foodstuffs. Finally, based on the factors that affect the formation of HAAs in heat-processed foodstuffs, such as the cooking method, food type, the recipe, and the content of substances with enhancing or inhibiting effects on the formation of HAAs, this review also highlights the most promising strategies for mitigating HAAs, which include adjusting cooking methods or process conditions, adding natural product extracts, antioxidants or other compounds, or reasonable selection of types of foodstuff. The review intends to provide a broad but comprehensive understanding of the formation, extraction, purification, analytical methods, and possible mitigation strategies for isolated and identified HAAs.

Rapid determination of hexavalent chromium in textiles by a novel ammonium pyrrolidine dithiocarbamate derivatization combined with UHPLC-MS/MS.

Hexavalent chromium is mainly determined by traditional spectrophotometry, atomic absorption spectrometry, and ion chromatography methods. In the present work, a reliable ultra high performance liquid chromatography with tandem mass spectrometry method was firstly developed for the determination of hexavalent chromium in textiles. The sample was extracted by acetic acid/sodium acetate buffer solution and followed by derivatization with ammonium pyrrolidine dithiocarbamate. The resulting derivative product was extracted by ethyl acetate, separated on a C18 column, and detected through electrospray ionization source in the positive mode with multiple reaction monitoring conditions. The derivatization reaction conditions were investigated and optimized. The developed method was validated in terms of the sensitivity, linearity range, matrix effects, recovery, accuracy, intra- and interday precision. Results showed that the calibration curves of pure solvent and matrix were linear over the selected concentration ranges of 0.1-20.0 µg/L. The achieved instrument and method limit of quantification were 0.1 and 40.0 µg/kg, respectively. Recoveries were calculated at three spiked concentrations and the values were between 92.2 and 103% with relative standard deviation values of 2.7-4.9% for intra-day precision and 6.1% for inter-day precision. Successful analysis of hexavalent chromium in practical textiles indicated that there was hexavalent chromium contamination in textiles.

Simultaneous determination of glycol ethers and their acetates in cosmetics by gas chromatography with mass spectrometry.

A gas chromatography with mass spectrometry method was developed for the simultaneous determination of ten kinds of glycol ethers and their acetates in cosmetics. The samples were extracted with methanol/ethyl acetate (80:20, v/v), further treated with vortex and ultrasound, and analyzed by gas chromatography with mass spectrometry. The concentration of each analyte was calibrated by the external standard method. Under the optimal conditions, the analytes showed linear relationship in the range of 0.05-25 mg/L with determination coefficients larger than 0.9987. The limits of detection and quantification were in the range of 0.09-0.59 and 0.31-1.95 mg/kg, respectively. The average recoveries of three spiked levels were 80.2-105.4% with intra- and interday precisions of 1.1-6.3 and 1.9-6.5%, respectively. Method validation from different labs confirmed the satisfactory recoveries and precisions. This method shows advantages of simple, high sensitivity, and high recovery, which can be applied to the detection of glycol ethers and acetates in cosmetics.

Simultaneous determination of eight alkaloids and oleandrin in herbal cosmetics by dispersive solid-phase extraction coupled with ultra high performance liquid chromatography and tandem mass spectrometry.

We utilized ultra-high performance liquid chromatography with tandem mass spectrometry and dispersive solid-phase extraction to develop a new method for the detection of nine analytes (scopolamine, cephaeline, strychnine, hyoscyamine, brucine, hydrastine, ajmalicine, colchicine, and oleandrin) in herbal cosmetics. Acetonitrile/water and 2-propylaminoethylamine were used to disperse and purify during the dispersive solid-phase extraction step. The analytes were separated by a Waters UPLC HSS T3 column and detected through electrospray ionization source in the positive mode with multi-reaction monitoring conditions. Under the optimal conditions, the calibration curves were linear in the range of 0.2-100.0 µg/L with the correlation coefficients higher than 0.995. The method limit of quantitation (S/N = 10) were 5.0 µg/kg for oleandrin and 1.0 µg/kg for the other eight alkaloids. The mean recoveries at three spiked concentration levels of 1.0-10.0 µg/kg were in the range of 86.9-116.5% with the intra-day relative standard deviations (n = 6) ranging from 2.4 to 8.8%, and inter-day relative standard deviations ranging from 2.7 to 5.7%. This method is accurate, simple and rapid, and has been applied to the quality supervision of herbal cosmetics in Guangzhou.

[Attenuated total reflection-fourier transform infrared spectroscopic study of dried shark fin products].

Sixty-four pieces of shark fin dried products (including real, fake and artificial shark fin products) and real products coated with gelatin were rapidly and nondestructively analyzed by attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR). The characteristic of IR spectrograms among the above four kinds of samples were systematically studied and comparied, the results showed that the spectrograms of the same kind of samples were repeatable, and different kinds of shark fin products presented significant differences in the spectrograms, which mainly manifested as the specific absorption peaks of amido bonds in protein (1650, 1544 cm(-1)) and skeletal vibration in polysaccharide (1050 cm(-1)). The spectrograms of real shark fins were characterized by the strong absorption peaks of protein characteristic amide I and II absorbent (1650, 1544 cm(-1)) and relatively weak C--O--C vibration absorbent (1050 cm(-1)) owing to the high content of protein and relatively low level of polysaccharide. For fake shark fin products that were molded form by mixing together with the offcut of shark, collagen and other substances, the introduction of non-protein materials leaded to the weaker amido bonds absorbent than real products along with a 30 cm(-1) blue shift of amide I absorbent. Opposite to the real sample, the relatively strong absorption peak of polysaccharide (approximately 1047 cm(-1)) and barely existed amide absorbent were the key features of the spectrogram of artificial samples, which was synthersized by polysaccharide like sodium alginate. Real samples coated with gelatin, the peak strength of protein and polysaccharide were decreased simultaneously when the data collection was taken at the surface of sample, while the spectrogram presented no significant difference to real samples when the data was collected in the section. The results above indicated that by analyzing the characteristic of IR spectrograms and the value range of Apro/Apol collected by ATR-FTIR method could perform the undamaged and rapid identification for shark fins.

Dispersive liquid-liquid microextraction combined with ultrahigh performance liquid chromatography/tandem mass spectrometry for determination of organophosphate esters in aqueous samples.

A new technique was established to identify eight organophosphate esters (OPEs) in this work. It utilised dispersive liquid-liquid microextraction in combination with ultrahigh performance liquid chromatography/tandem mass spectrometry. The type and volume of extraction solvents, dispersion agent, and amount of NaCl were optimized. The target analytes were detected in the range of 1.0-200 µ g/L with correlation coefficients ranging from 0.9982 to 0.9998, and the detection limits of the analytes were ranged from 0.02 to 0.07 µg/L (S/N = 3). The feasibility of this method was demonstrated by identifying OPEs in aqueous samples that exhibited spiked recoveries, which ranged between 48.7% and 58.3% for triethyl phosphate (TEP) as well as between 85.9% and 113% for the other OPEs. The precision was ranged from 3.2% to 9.3% (n = 6), and the interprecision was ranged from 2.6% to 12.3% (n = 5). Only 2 of the 12 selected samples were tested to be positive for OPEs, and the total concentrations of OPEs in them were 1.1 and 1.6 µg/L, respectively. This method was confirmed to be simple, fast, and accurate for identifying OPEs in aqueous samples.

Recent advances in the authentication (geographical origins, varieties and aging time) of tangerine peel (Citri reticulatae pericarpium): A review.

The consumption of tangerine peel (Citri reticulatae pericarpium, CRP) has been steadily increasing worldwide due to its proven health benefits and sensory characteristics. However, the price of CRP varies widely based on its origin, variety, and aging time, which has led many manufacturers to offer inferior products by exploiting the sensory similarity of CRP, seriously undermining consumers' interests. Therefore, it is essential to identify the authenticity of the CRP. In this study, the research progress on the authenticity of CRP from different origins, years and varieties over the past 10 years and the application and prospects of the main technologies and techniques were reviewed. The advantages and disadvantages of the commonly used methods were also summarized and compared. Mass spectrometry-based and spectroscopy-based techniques are the most commonly used methods for analyzing CRP authenticity. However, designing fast, non-destructive and green methods for identifying CRP authenticity would be the future trend.

Exposure of Reproductive-Aged Women to Multiple Metals and Its Associations with Unexplained Recurrent Miscarriage.

Exposure to heavy metals exerts toxic effects on female reproduction and embryo development. This study examined the exposure of patients with unexplained recurrent miscarriage (uRM) to multiple metals and the correlations among exposures to different metals. A total of 275 participants were enrolled, including 43 healthy women without previous miscarriage (the control group) and 232 uRM women (the case group); among these uRM women, 159 had two miscarriages (2M), 42 had three miscarriages (3M) and 31 had four or more miscarriages (≥4M). A total of 22 elements were measured in serum samples via inductively coupled plasma-mass spectrometry. The levels of calcium (104.37 mg/L vs. 92.65/93.02/92.61/92.47 mg/L) and selenium (131.85 µg/L vs. 117.80/118.04/115.88/124.35 µg/L) were higher in the controls than in the total uRM group and the 2M, 3M and ≥4M subgroups. The level of vanadium was significantly lower in the controls than in the total uRM group (0.15 µg/L vs. 0.23 µg/L), and the level of lead was lower in the controls than that in the total uRM group and the 2M, 3M and ≥4M subgroups (0.01 µg/L vs. 0.28/0.18/0.63/0.34 µg/L). After adjusting for age, body mass index and education level, calcium and selenium exposure were consistently negatively associated with miscarriage, while lead exposure was positively associated with miscarriage. In addition, the correlations among exposures to different metals slightly differed between the control and uRM groups. Therefore, changes in some metal elements in the blood might be related to the risk of uRM.

Development and validation of a multianalyte method for quantification of aflatoxins and bongkrekic acid in rice and noodle products using PRiME-UHPLC-MS/MS method.

An analytical method based on PRiME (process, robustness, improvements, matrix effects, ease of use) HLB purification followed by the ultra-high liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) detection has been developed for the determination aflatoxin B1, B2, G1 and G2 and bongkrekic acid in rice and noodle products. Five toxins were separated on a Waters BEH C18 column by gradient elution, scanned by ESI+ and ESI- dynamic switching and detected with MRM mode. LOD, LOQ, matrix effects, accuracy and precision of the developed method were investigated. Under the optimal sample pretreatment conditions, high sensitivity (LOQs: 0.20-0.40 µg/kg), good recoveries (80.5%-106.6%) and acceptable precision (2.4%-7.2%) were obtained for the analysis of the four aflatoxins and bongkrekic acid. This method was successfully applied to the analysis of rice and noodle products, demonstrating its applicability and suitability for the routine analysis of aflatoxins and bongkrekic acid in rice and noodle products.

Simultaneous determination of twelve mycotoxins in edible oil, soy sauce and bean sauce by PRiME HLB solid phase extraction combined with HPLC-Orbitrap HRMS.

A solid phase extraction-high-performance liquid chromatography-tandem Orbitrap high resolution mass spectrometry (HPLC-Orbitrap HRMS) method was established for the determination of 12 mycotoxins (ochratoxin A, ochratoxin B, aflatoxin B1, aflatoxin B2, aflatoxin G1, aflatoxin G2, HT-2 toxin, sterigmatocystin, diacetoxysciroenol, penicillic acid, mycophenolic acid, and citreoviridin) in edible oil, soy sauce, and bean sauce. Samples were extracted by 80:20 (v:v) acetonitrile-water solution, purified by PRiME HLB column, separated by aQ C18 column with mobile phase consisting of 0.5 mmol/L ammonium acetate-0.1% formic acid aqueous solution and methanol. The results showed that the limits of detection (LODs) and limits of quantification (LOQs) of 12 mycotoxins were 0.12-1.2 µg/L and 0.40-4.0 µg/L, respectively. The determination coefficients of 12 mycotoxins in the range of 0.20-100 µg/L were > 0.998. The average recoveries in soy sauce and bean sauce were 78.4-106.8%, and the relative standard deviations (RSDs) were 1.2-9.7% under three levels, including LOQ, 2× LOQ and 10 × LOQ. The average recoveries in edible oil were 78.3-115.6%, and the precision RSD (n = 6) was 0.9-8.6%. A total of 24 edible oils, soy sauce and bean sauce samples were analyzed by this method. AFB1, AFB2, sterigmatocystin and mycophenolic acid were detected in several samples at concentrations ranging from 1.0 to 22.1 µg/kg. The method is simple, sensitive, and rapid and can be used for screening and quantitative analysis of mycotoxin contamination in edible oil, soy sauce, and bean sauce.

Alkaline lysis-recombinase polymerase amplification combined with CRISPR/Cas12a assay for the ultrafast visual identification of pork in meat products.

The "Horsemeat Scandal" makes people pay more attention to the meat authenticity. However, expensive equipment, complicated operations, and professional personnel of current methods limit their field testing. In this study, CRISPR/Cas12a combined with recombinase polymerase amplification was used to establish a sensitive and rapid detection method for pig-derived component. The detection limit can reach to 10-3 ng for pig DNA and be completed within 30 min. Beef and pork binary mixture models under different processing conditions of raw meat, boiled, and high-pressure were tested. Combining with two different DNA extraction methods, the detection limits of pork are as low as 0.1% and 0.001% (w/w), respectively. After 125 commercial products are tested, the results are completely consistent with the Chinese national standard real-time PCR method. This method not only has better detectability, but also can quickly and conveniently realize the visual identification of pig-derived ingredients, thus is suitable for on-site detection.

Fragmentation pathway of hypophosphite (H2PO2-) in mass spectrometry and its determination in flour and flour products by LC-MS/MS.

The fragmentation pathway of H2PO2- in MS was obtained by Orbitrap HRMS and the reverse confirmation was carried out by the neutral loss detection experiment. The results showed that H2PO2- with even electron ion would produce the neutral loss of 2H and form a new even electron ion with a pair of lone-pair electrons. Based on this, a LC-MS/MS method was developed for the determination of H2PO2- in flour and flour products. The H2PO2- was separated on an Acclaim Trinity P1 composite ion exchange column, and then detected by MS/MS under MRM mode. Finally, the developed method was validated in terms of the linearity, selectivity, accuracy, precision and matrix effect. The method showed a good linearity (R2＞0.999) in the concentration range of 50 âˆ¼ 1500 µg/L. The LOD and LOQ for H2PO2- were 10.0 mg/kg and 30.0 mg/kg, respectively. The average recoveries and RSDs (n = 6) were 93.0%∼102.9% and 2.6 âˆ¼ 5.6%, respectively.

Banana-peel-derived magnetic porous carbon as effective adsorbent for the enrichment of six bisphenols from beverage and water samples.

Functionalized magnetic nanoporous carbon derived from banana peel was synthesized through carbonization, porogenesis, carboxylation and magnetization using banana peel and was successfully used as a magnetic solid phase extraction (MSPE) material for the enrichment of six bisphenols (BPs) from beverage and water samples. After the optimization of MSPE process, the enrichment factors of six target analytes were in the range of 74-112 for water samples, and 15-22 for beverage samples. Then, high-performance liquid chromatography-quadrupole-Orbitrap high-resolution mass spectrometry (HPLC-Q Orbitrap-HRMS) was used for the separation and determination of the target analytes. Results showed that the extraction recoveries for 6 BPs were in the range of 71.9-108.4% with an RSD of 2.5-7.5% (n = 6). These results demonstrated that the as-prepared material could efficiently enrich some aromatic compounds and the proposed method is reliable and robust for the determination of BPs in water and beverage samples.

Perchlorate occurrence in foodstuffs and water: Analytical methods and techniques for removal from water - A review.

Perchlorate (ClO4-), a type of contaminant with high diffusivity and durability, has been widely detected in water and foodstuffs, arousing a global concern. It can interfere with normal function of the human thyroid gland, affecting human health. Therefore, determination of perchlorate in water and foodstuffs, and removal from water are important. This review focuses on the occurrence of perchlorate, mainly in water and foodstuffs, and provides an overview of analytical methods for determination of perchlorate over the last two decades. In addition, merits and drawbacks of the various methods have been considered. This review also highlights the most commonly used approaches for removal of perchlorate from water. Finally, current trends and future perspectives in determination of perchlorate and removal from water are proposed. This review provided a comprehensive understanding of perchlorate occurrence and its removal from water, and had practical significance in reducing the harm of perchlorate to human.

Determination of bongkrekic acid and isobongkrekic acid in rice noodles by HPLC-Orbitrap HRMS technology using magnetic halloysite nanotubes.

The existing extraction and detection methods of bongkrekic acid (BKA) and isobongkrekic acid (IBKA) are complex, time-consuming and solvent-consuming. In this work, a simple and fast pre-concentration procedure based on Fe3O4/HNTs was developed for the determination of BKA and IBKA in rice noodles using HPLC-Orbitrap HRMS. The structure and morphology of Fe3O4/HNTs was characterized by means of XRD, SEM, FT-IR and VSM. Parameters affecting the extraction efficiency including adsorbent amount, pH, extraction time, type and volume of eluent were investigated by employing the response surface method. Results indicated that the proposed method had favorable linearity in the concentration range of 2-200 µg/L with a correlation coefficient >0.998. Method LOD and LOQ were 0.3 µg/kg and 1.0 µg/kg, respectively. Finally, the method was successfully applied to determine BKA and IBKA in rice noodle samples from southern China with recoveries ranging from 79.8% to 102.6% and relative standard deviation (RSD) of 4.2%-7.1%.

Fluorine and nitrogen functionalized magnetic graphene as a novel adsorbent for extraction of perfluoroalkyl and polyfluoroalkyl substances from water and functional beverages followed by HPLC-Orbitrap HRMS determination.

Most of the reported magnetic adsorbents are difficult to absorb multi-class of per- and polyfluoroalkyl substances (PFASs), especially the short-chain PFASs. In this work, a novel fluorine and nitrogen functionalized magnetic graphene (G-NH-FBC/Fe2O3) was first synthesized and characterized by scanning electron microscope (SEM), Fourier Transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). The as-prepared G-NH-FBC/Fe2O3 was utilized as adsorbents for the magnetic solid-phase extraction (MSPE) of 19 PFASs from water and functional beverages and showed excellent adsorption capacity probably due to the hydrophobic interaction. Under the optimal pretreatment and instrumental conditions, a selective and sensitive high performance liquid chromatography Orbitrap high resolution mass spectrometry (HPLC-Orbitrap HRMS) method was developed for the determination of PFASs. Results indicated that the proposed method had favorable linearity (R2 ≥ 0.994) within a wide range of concentrations. Limit of detection (LOD) and limit of quantification (LOQ) for the developed method ranged from 3 ng/L to 15 ng/L and 10 ng/L to 49 ng/L, respectively. Finally, the method was successfully applied to determine PFASs in drinking water, river water, tap water, factory drainage and functional beverages with recoveries ranging from 71.9% to 117.6% and relative standard deviation of <10%. The prepared G-NH-FBC/Fe2O3 was easy to recycle and could be reused for five times without significant decrease in extraction recoveries of PFASs. These results demonstrated that this novel magnetic G-NH-FBC/Fe2O3 could efficiently enrich PFASs and the proposed method is reliable and robust for the determination of PFASs in water and beverage samples.

Analysis of heterocyclic aromatic amine profiles in Chinese traditional bacon and sausage based on ultrahigh-performance liquid chromatography-quadrupole-Orbitrap high-resolution mass spectrometry (UHPLC-Q-Orbitrap-HRMS).

Ultrahigh-performance liquid chromatography coupled to quadrupole Orbitrap high-resolution mass spectrometry (UHPLC-Q-Orbitrap-HRMS) was used for the screening and determination of 14 heterocyclic aromatic amines (HAAs) in Chinese traditional bacon and sausage. HAAs were extracted from samples using sodium hydroxide solution with acetonitrile, and purified by solid-phase extraction. UHPLC-Q-Orbitrap-HRMS acquired full MS data for quantification, and UHPLC-Q-Orbitrap-Full MS/dd-MS2 (i.e., data-dependent scan mode) obtained product ion spectra for identification. Quantification was achieved using matrix-matched standard calibration curves along with the use of isotope labeled standards as internal standards. Linearity was observed in the range of 0.2-500 µg/L for 14 HAAs, with determination coefficients (R2) greater than 0.997. Limits of detection and limits of quantification were in the ranges of 0.1-0.8 µg/kg and 0.3-2.5 µg/kg, respectively. UHPLC-Q-Orbitrap-HRMS demonstrated acceptable performance for quantification and confirmation of HAAs, while UHPLC-Q-Orbitrap-Full MS/dd-MS2 along with library matching showed great potential for screening and confirmation of unknown HAAs in meat products.

High throughput analysis of 21 perfluorinated compounds in drinking water, tap water, river water and plant effluent from southern China by supramolecular solvents-based microextraction coupled with HPLC-Orbitrap HRMS.

The present work reported a high-throughput strategy for the analysis of 21 perfluorinated compounds (PFCs) in drinking water, tap water, river water and plant effluent from southern China by supramolecular solvent (SUPARS) vortex-mixed microextraction combined with high performance liquid chromatography-Orbitrap high resolution mass spectrometry (HPLC-Orbitrap HRMS). The SUPRAS without heating assistance is less solvent-consumption, meeting the requirements for green environmental protection and sustainable development. Parameters in the microextraction such as volume of dodecanol and tetrahydrofuran (THF), vortexing extraction and centrifugation time, salt concentration were investigated. The optimal extraction conditions were 250 µL of undecanol, 1.0 mL of THF and 20.0% (w/v, 4 g) NaCl. Under the optimum conditions, method limit of detection and method limit of quantitation in the ranges of 0.01-0.08 µg/L and 0.03-0.25 µg/L, good recoveries (72.5-117.8%) and intra-day precision (1.1-11.2%, n = 6), high enrichment factors (48-78) were obtained. The developed method was successfully applied for analysis of PFCs in 13 drinking water, tap water, river water and plant effluent samples collected from southern China. Perfluorobutane sulfonic acid was detected in one river water with concentration of 0.48 µg/L and 1H,1H,2H,2H-Perfluorooctane sulfonic acid was detected in one river water and two plant effluent samples with concentrations in the range of 0.14-0.67 µg/L.

A novel approach for simultaneous analysis of perchlorate (ClO4-) and bromate (BrO3-) in fruits and vegetables using modified QuEChERS combined with ultrahigh performance liquid chromatography-tandem mass spectrometry.

Perchlorate (ClO4-) and bromate (BrO3-) are mainly determined by ion chromatography methods. The present work aims to develop a modified QuEChERS combined with ultrahigh performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for simultaneous analysis of ClO4- and BrO3- in fruits and vegetables including cherry tomato, strawberry, tomato, potato, lettuce and pakchoi. Two target inorganic anions were separated on a Diamonsil C18(2) column by gradient elution, scanned in ESI negative mode and detected under multiple reactions monitoring (MRM). Limit of detection (LOD) and method limit of quantification (MLOQ), matrix effect, accuracy and precision of the developed method were investigated. Results were linear in their concentration ranges, with coefficients of determination (r2) bigger than 0.999. LODs for ClO4- and BrO3- were 0.1 µg/L and 0.5 µg/L, respectively. The validated method provided sufficient selectivity, sensitivity and accuracy to screen for ClO4- and BrO3- with ignorable matrix effects. Recoveries for different kinds of negative samples at 3 spiked levels were between 82.0% and 99.5%. Both intraday-precision and interday-precision were satisfactory, showing RSDr values in the range of 2.1-7.1% and RSDR values in the range of 7.2-10.8%. The proposed method was successfully applied to determine target inorganic anions in several fruits and vegetables. Perchlorate was detected in 12 vegetable samples with the concentrations ranged from 21 µg/kg to 162 µg/kg. Results indicated that there was wide ClO4- contamination in vegetables, confirming its urgency for monitoring harmful inorganic anions in our daily consumed vegetables.

Development and comparison of single-step solid phase extraction and QuEChERS clean-up for the analysis of 7 mycotoxins in fruits and vegetables during storage by UHPLC-MS/MS.

A robust and sensitive UHPLC-MS/MS method was developed for the analysis of seven mycotoxins in fruits and vegetables. The variations of seven mycotoxins concentrations during storage were also determined for the first time. Solid phase extraction (SPE) and QuEChERS clean-up were compared, and extraction was finally performed with acetonitrile under acidic conditions followed by HLB SPE purification. Seven mycotoxins were separated on a C18 column by gradient elution, scanned by ESI+ and ESI- dynamic switching and detected with MRM mode. LOD and LOQ, matrix effect, accuracy and precision of the developed method were investigated. Results were linear in their concentration ranges for all mycotoxins with R2 being greater than 0.999. LODs and LOQs were ranged from 0.05 to 3.0 µg/kg and 0.2 to 10.0 µg/kg, respectively. Average recoveries were between 81.1% and 116% with intraday- and interday-precision being in the ranges of 3.0-6.2% and 4.2-6.1%, respectively. The validated method provides sufficient selectivity, sensitivity and accuracy to screen for seven mycotoxins at trace levels, without using standard addition or matrix-matched calibration to compensate for matrix effects. The method was successfully applied for mycotoxins analysis in fruits and vegetables. None were detected in fresh samples, but AOH and AME were detected in strawberry, and TeA was detected in tomato fruits during long-term storage. Their concentrations were in the range of 3.6-165.3 µg/kg from 3 days to 60 days and significantly increased along with storage time.