The food system of Zhejiang Province, a major coastal province in China, includes a wide variety of products, such as canned foods, aquatic products, vegetables, fruits, and tea, all of which may serve as potential sources of tin (Sn) exposure. However, no systematic study has assessed the distribution and dietary exposure risk of Sn across food categories in the province, and a compound-specific evaluation of organotin compounds is lacking. Therefore, we investigated the occurrence of Sn in commonly consumed foods and assessed dietary exposure risks among different age groups in Zhejiang Province. In total, 2014 samples from five major food categories-fresh vegetables, fresh fruits, tea, fresh aquatic products, and canned foods-were collected using a multistage stratified random sampling strategy. The Sn concentrations were measured using inductively coupled plasma mass spectrometry, with non-detection replaced by half the detection limit. Dietary intake data were derived from the 2015-2017 Nutrition and Health Surveillance using a 3-day, 24 h recall. The estimated daily intake and total hazard quotient (THQ) were calculated for age-specific risk assessments under multiple exposure scenarios. Fresh vegetables, fruits, tea, and most aquatic products had low Sn concentrations, whereas canned foods, particularly fruits, fungi, and meat products, had higher Sn concentrations. THQ values remained well below 1 across all food categories, indicating minimal health risks under typical consumption patterns, although lifetime exposure estimates suggested that canned foods could approach toxicological benchmarks earlier under high-consumption scenarios. A supplementary assessment of organotin compounds, which are highly toxic even at low fractions of total Sn, used a reverse dietary risk approach and probabilistic modeling. Canned foods and fresh aquatic products exhibited the lowest minimum conversion rates (0.16% and 0.37%, respectively), indicating that they are the most susceptible to organotin risk, whereas fresh fruits (7.77%) and tea (18.67%) required much higher proportions. Due to limited literature, further scenario- and probabilistic-based assessments focused on fresh aquatic products, revealing that typical exposure levels are generally safe, but children ≤ 6 years of age are the most vulnerable. Although overall Sn exposure is low, intake of highly processed foods, particularly canned products, should be limited in young children's diets. These findings highlight that even small shifts in Sn speciation within high-risk food categories can lead to excessive tolerable daily intakes. This study provides a scientific reference for dietary Sn risk assessment and food safety management.

Ready-to-cook dishes have flooded into global markets, raising widespread food safety concerns. N-nitrosamines (NAs) are recognized carcinogens generated during food processing, yet few contamination surveys have been reported for NAs in ready-to-cook dishes. To address the analytical challenges posed by complex matrices of ready-to-cook dishes, a steam distillation-solid phase extraction pretreatment system was optimized (2 mL hexane for cleanup; 10 mL dichloromethane for elution) and coupled with gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS) and gas chromatography quadrupole time-of-flight mass spectrometry (GC-Q/TOF MS). This study established a reliable method for detecting 11 types of NAs. The comparative evaluation of the two platforms was conducted and the validated method was applied to assess NAs contamination levels in 91 ready-to-cook dish samples. Both platforms exhibited good linearity (10-200 μg/L, r ≥ 0.999). Limits of detection (LODs) for GC-Q/TOF MS (0.002-0.89 μg/kg) were slightly lower than GC-MS/MS (0.02-1.08 μg/kg). Recoveries ranged from 80.7% to 119.7% with relative standard deviations <9.1% for both platforms. GC-Q/TOF MS showed superior anti-interference capability. N-nitrosodimethylamine (NDMA) and N-nitrosodiphenylamine (NDPHA) showed detection rates of 34.1% and 52.7%, with maximum concentrations in "Octopus tentacle slices" and "Fish soup," respectively. Taking into account the detection rates and the presence of high-concentration samples, the category of aquatic products requires urgent attention. Overall, this study provides a reliable method and important data for evaluating NAs contamination in ready-to-cook dishes, highlighting the need for future research on health risk assessment and production specification control.

OBJECTIVE:To develop and validate a gas chromatography-mass spectrometry(GC-MS) method for the simultaneous determination of 19 phthalic acid esters(PAEs), including o-, m-, and p-di(2-ethylhexyl) terephthalate, in commercially available prepared dishes, with a focus on meat and aquatic product-based categories. METHODS:In accordance with China&apos;s national standard GB 5009.271-2016 Food Safety National Standard-Determination of Phthalate Esters in Foods, homogenized samples were extracted with hexane, purified using a Silica/PSA solid-phase extraction column, and separated via a capillary chromatographic column. Analysis was performed by GC-MS in selected ion monitoring(SIM) mode, with quantification achieved through the internal standard method. Market samples of meat-and aquatic product-based prepared dishes were tested. RESULTS:The method demonstrated excellent linearity for 19 plasticizing agent within concentration ranges of 0.02-1.00 mg/kg(0.50-10.00 mg/kg for diisononyl phthalate(DINP)), with correlation coefficients(r) ≥ 0.993. At spiked levels of 0.1, 0.3 and 1.0 mg/kg, mean recoveries ranged from 78.0% to 119.4%, with relative standard deviations(RSDs) of 0.5%-11.8%(n=6). Detection frequencies for di(2-ethyl) hexyl phthalate, diisobutyl phthalate, dibutyl phthalate and di(2-ethyl) hexyl terephthalate reached 100%, 94.7%, 94.7%, and 78.9%, respectively, while the remaining 15 PAEs were below the limit of detection(LOD). Concentration ranges for detectable plasticizing agent were 0.10-2.60 mg/kg(di(2-ethyl) hexyl phthalate), not detected(ND)-0.38 mg/kg(diisobutyl phthalate), ND-0.35 mg/kg(dibutyl phthalate), and ND-0.40 mg/kg(di(2-ethyl) hexyl terephthalate). CONCLUSION:The optimized GC-MS method exhibits high applicability for the simultaneous quantification of 19 PAEs in prepared dishes.

Diazepam, commonly used in freshwater fish transport and aquaculture, poses potential food safety and public health risks due to its residues and metabolites. However, current monitoring efforts primarily focus on the parent drug and its major metabolites, leaving potential toxic transformation products uncharacterized. This study reports two novel metabolites (BP-246, 5-chloro-2-(methylamino)phenyl)(phenyl)methanone, and BP-271, 6-chloro-1-methyl-4-phenylquinazolin-2(1 H)-one) in freshwater fish muscle, a matrix in which these compounds have not been previously reported, using liquid chromatography-Orbitrap high-resolution mass spectrometry (LC-Orbitrap HRMS). Using ProTox3.0 and ADMETlab3.0 for toxicity prediction revealed that BP-246 and BP-271 exhibit high blood-brain barrier permeability, neurotoxicity and ecotoxicity. A sensitive and validated ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed for the simultaneous quantification of diazepam, three established metabolites (nordiazepam, oxazepam, temazepam), and the two novel compounds in fish tissue. Sample preparation involved acetonitrile ultrasonication extraction followed by solid-phase extraction (SPE) purification. Matrix-matched calibration curves demonstrated excellent linearity ( R2 > 0.999) over the range of 0.2-10 µg/kg. Method recovery ranged from 78.5% to 119.9%, with intra-day and inter-day relative standard deviations (RSDs) below 9.9% and 9.1%, respectively. Limits of detection (LOD) and quantification (LOQ) were 0.05-0.06 µg/kg and 0.15-0.20 µg/kg, respectively. The method showed robust selectivity and consistent retention times. When applied to 10 market-sourced, diazepam-positive fish samples, the method successfully revealed differential metabolite profiles, enabling rapid, high-throughput monitoring of diazepam and transformation products in commercial fish products. These findings provide a basis for comprehensive risk assessment and regulatory control of diazepam residues in the food supply chain.

(1) Background: Given the contamination risks of organotin compounds (OTCs) in fish oil and their potential threat to consumer health, this study addresses the analytical challenges posed by complex matrices and OTC degradation. A highly efficient and sensitive gas chromatography-mass spectrometry (GC-MS) method was established and optimized. This method enables the simultaneous qualitative and quantitative determination of multiple OTCs, providing reliable technical support for the quality and safety monitoring of dietary supplements. (2) Methods: After cryogenic extraction, sorbent cleanup, and derivatization with sodium tetraethylborate, samples were subjected to n-hexane extraction and further purification usiss identification and quantified using the internal standard method. This approach significantly improved separation efficiency and detection throughput through systematic optimization of pretreatment and instrumental conditions. (3) Results: Results showed that using 3% acetic acid-acetonitrile for the extraction of 0.5 g spiked fish oil improved efficiency by over 20% compared to single solvents. A dual-stage cleanup using 0.2 g HCC18 combined with a Florisil column provided optimal delipidation, with recoveries remaining above 80%. The nine organotins exhibited good linearity (R² ≥ 0.99) in the range of 2.0-750.0 μg/L. The limits of detection (LOD) and quantification (LOQ) were 0.151-0.439 μg/kg and 0.453-1.317 μg/kg, respectively. Spiked recoveries ranged from 81.1% to 105% with RSDs of 0.99-5.73%. (4) Conclusions: This study significantly enhanced the performance of GC-MS for detecting organotin compounds in fish oil by introducing a systematically optimized dual-stage cleanup strategy combining HCC18 and Florisil. This approach effectively eliminated lipid interference, thereby improving accuracy and sensitivity. Method validation demonstrated the method's reliability and practicality. These findings provide a high-sensitivity, anti-interference detection solution for the dietary supplement industry, holding significant public health implications for reducing consumer exposure to neurotoxic substances.

Isoxazoline veterinary drugs, including afoxolaner, fluralaner, and lotilaner, are extensively used to control ectoparasite infestations, necessitating robust analytical methods for residue monitoring in animal-derived foods. In this study, a sensitive and robust liquid chromatography–tandem mass spectrometry (LC–MS/MS) method was developed for the simultaneous determination of these compounds. Sample preparation involved extraction with acetonitrile, phase partitioning with anhydrous MgSO₄, and rapid clean-up using a Captiva EMR-Lipid pass-through cartridge. To ensure quantitative reliability, stable isotope-labeled internal standards were employed. The method exhibited excellent linearity (R² > 0.999) across a concentration range of 0.6–150 μg/kg. Limits of detection (LODs) and quantification (LOQs) were 0.2 and 0.6 μg/kg, respectively. Across five complex matrices (chicken muscle, egg, mutton, pork, and pork liver), the mean recoveries ranged from 90.8% to 111.5%, with relative standard deviations (RSDs) ≤ 5.19%. This validated protocol offers a highly efficient and robust analytical tool for routine isoxazoline residue surveillance in diverse animal-derived matrices.

This study aimed to evaluate ten essential minerals - sodium (Na), magnesium (Mg), phosphorus (P), potassium (K), calcium (Ca), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), and selenium (Se) - in 35 aquatic products from Guangxi using ICP-MS following microwave-assisted digestion, and to assess their nutritional profiles through chemometric and INQ approaches. Method validation showed linearity (r > 0.999), limits of detection (LODs) of 0.002-6.3 mg kg(-1), and accuracy against two certified reference materials with relative standard deviations (RSDs) of 0.92%-11.7%. Finfish were broadly abundant in P and Ca, with Ca peaking in whole-eaten freshwater fish. Mollusks showed higher Fe and Zn than most finfish. Principal Component Analysis (PCA) and hierarchical cluster analysis (HCA) separated finfish from invertebrates enriched in Na, Mg, Fe, and Cu, and distinguished samples along a Ca-P axis. Index of Nutritional Quality (INQ) evaluation suggested high P and Se density across species, while bivalves and small fish may be prioritized to improve dietary Ca, Zn, and Fe supply. Elevated Na density in cephalopods and high Cu density in crustaceans highlight the need for species-specific dietary choices. This integrated assessment of western Chinese aquatic products provides evidence-based data for precision nutrition, though future speciation studies remain warranted.

Food preservatives are widely recognized as essential food additives that play critical roles in ensuring food safety， at the same time， the use of preservatives in food has been strictly regulated at home and abroad. Consequently， the accurate identification of various types and concentration levels of food preservatives is pivotal for safeguarding public health. This study aims to review the standardized methods for the detection of food preservatives at home and abroad， with a specific focus on the analytical characteristics and application status of liquid chromatography， and gas chromatography-mass spectrometry （GC-MS）. Furthermore， the emerging trends and future directions in the development of detection technologies for food preservatives are also going to be discussed.

Background:Pre-prepared dishes contain fats/oils, high protein, and complex seasonings, making sterol detection difficult due to multiple components and matrix interference. Given the market's analytical challenges, detecting sterols-key functional components affecting nutritional value-is practically vital. This study aims to develop a sensitive, selective GC-MS method for simultaneous qualitative and quantitative multi-component sterol analysis in pre-prepared dishes and to examine their compositional traits. Methods:After saponification treatment, the sample undergoes ultrapure water-assisted dispersion and n-hexane extraction. The extract is dried and subjected to derivatization reaction. The derivative is redissolved and analyzed by gas chromatography-mass spectrometry (GC-MS) for qualitative identification, with quantification performed using the internal standard method. This method optimizes sample pretreatment and chromatographic separation conditions, enhancing detection efficiency and separation effectiveness. Results:The six target sterol compounds exhibited good linearity within the concentration range of 1.0-100.0 μg/mL (correlation coefficients ≥0.99). The limits of detection (LODs) and limits of quantification (LOQs) were 0.05-5.0 mg/100 g and 0.165-16.5 mg/100 g, respectively. At low, medium, and high spiked concentrations, the average recoveries ranged from 87.0 to 106%, with relative standard deviations (RSDs, n = 6) of 0.99-9.00%. Application of this method to analyze actual pre-prepared dish samples revealed significant variations in cholesterol content among different dish categories, with meat ingredients playing a dominant role. The sterol composition exhibited marked diversity: ergosterol was not detected in pre-prepared dishes, while β-sitosterol, campesterol, and stigmasterol constituted the major components. Notable differences in sterol content and composition were observed across different categories of pre-prepared dishes, further confirming the impact of various meat raw materials and processing technologies on sterol levels. Conclusion:The GC-MS analytical method established in this study has been validated to demonstrate excellent reliability and applicability, providing an efficient analytical tool for precise detection of multi-component sterols in pre-prepared dishes. This method supports quality control and nutritional value assessment in the pre-prepared dish industry, facilitating product labeling standardization and informed consumer choices.

OBJECTIVE:A stable isotope dilution-through solid phase extraction(SPE)-ultra-performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS) method was established for rapid determination of diazepam and its three metabolites(nordiazepam, temazepam and oxazepam) in fish. METHODS:Sample was extracted with acetonitrile, then salted out with sodium chloride and degreased by freezing centrifugation. The acetonitrile layer diluted to a ratio of 90 percents with pure water, and through C_(18)/PSA SPE column for purification. Purification solution was collected with the first 1 mL discarded, and nitrogen blow to near dry.1.0 mL initial mobile phase was used for reconstitution, and then separated by BEH C_(18)(100 mm × 2.1 mm, 1.7 μm) chromatography column using 0.1% formic acid aqueous and 0.1% formic acid methanol at gradient elution, and detected with triple quadrupole mass spectrometry. RESULTS:One-step purification with C_(18)/PSA SPE column would effectively reduce matrix interference, simplify operation and improve work efficiency. The linear ranges of 4 target compounds were 0.2 to 10.0 ng/mL and the correlation coefficients were greater than 0.999. The recoveries were in the range of 92.0%-120.0% with the relative standard deviations ranging from 4.5%-10.7%(n = 6). The method limits of detection were 0.2 μg/kg. Then the established method was used for the determination of 10 positive fish samples, and the content of diazepam and nordiazepam were 68.4%-100% in fish samples, and it indicated that diazepam and nordiazepam were the main biomarker. CONCLUSION:The established method is simple, rapid, sensitive and selective, which is suitable for the simultaneous determination of diazepam and its three metabolites in fish.

In this study, we aimed to investigate the occurrence of rare earth elements (REEs) in commonly consumed foods and assess the dietary exposure risks among different age groups in Zhejiang Province. The results showed that tea and shrimp had the highest REE detection rates, reaching 100%. Of all the food categories examined, tea exhibited the highest REE concentrations, significantly exceeding those in other foods. This may be attributed to differences in moisture content, root absorption mechanisms, and processing methods. The concentration pattern of REEs in all samples occurred in the following order: cerium > lanthanum > yttrium > neodymium > neodymium > scandium > praseodymium > gadolinium > dysprosium. The light REEs/heavy REEs (HREEs) ratio was consistently > 2 but remained lower than the ratios observed in the soil and sediments, indicating a potential risk of HREE enrichment. Dietary exposure assessments revealed that the total REE intake among Zhejiang residents was below the established safety threshold (51.3 µg/kg BW/day), with children experiencing the highest exposure (3.71 µg/kg BW/day), primarily due to their lower body weight. In the assessment of individual rare earth elements, Ce exposure in children aged ≤6 years exceeded the toxicological reference value. However, this threshold was established based on studies in pregnant and lactating populations and might not be directly applicable to young children. Therefore, overall dietary exposure to individual REEs remains within safe limits. REE exposure from tea consumption did not pose a health risk, even for habitual tea drinkers. These findings underscore the importance of continuous monitoring of REE accumulation in food and additional research on the potential long-term health effects, even though the current exposure levels of REEs are below the established safety limit. This is especially important considering the bioaccumulative nature of REEs and the limited paucity of toxicological data, particularly in vulnerable populations.

This study aimed to assess the prevalence of four Alternaria toxins (alternariol [AOH], alternariol monomethyl ether [AME], tenuazonic acid [TeA], and tentoxin [TEN]) in various foods and assess the risk of Alternaria-toxin exposure in Zhejiang Province, China. A total of 325 samples were collected in this study, and at least one type of Alternaria toxin was detected in 53.85% of the samples. Wheat flour had a high detection rate of 97.41%, and TeA was the most prevalent compound in terms of concentration and detection rate. Assessment of Alternaria toxins using the threshold of toxicological concern (TTC) method showed that the majority of the population had a low exposure risk. Population-wide dietary exposure assessment suggested a potential health risk for some residents with 95th percentile (P95) assessment values 0.0038, 0.0128, and 0.0047 µg/kg b.w. for AOH from wheat flour and AOH and AME from Coix rice, respectively, exceeding the TTC value of 0.0025 µg/kg b.w. Probabilistic assessment showed that the mean exposure of children aged ≤6 years to AOH via wheat flour for P92 and of those aged 7–12 years for P93 were both 0.0025 µg/kg b.w. Exposures to TeA and TEN were within the acceptable limits (below the TTC value of 1.5 µg/kg b.w.). Age-group probabilistic and point assessments indicated that children aged ≤6 and 7–12 years are at higher exposure risk. This study provides a useful reference for developing limiting values and legislation for Alternaria toxins in food.

We developed a simple, rapid, accurate, and sensitive method for the determination of acrylamide (AA) in coffee based on ultra-performance liquid chromatography tandem triple quadrupole mass spectrometry (UPLC-MS/ MS). The AA in coffee was simply extracted with water and then defatted with dichloromethane. After that, concentration and purification were achieved through solid-phase extraction techniques. The calibration curve for AA showed excellent linearity over the concentration range of 0.5-500 ng/mL, with a correlation coefficient (r) in excess of 0.999. Furthermore, our method exhibited high precision, as evidenced by intra- and inter-day coefficients of variation of less than 5.7 % and 6.3 %, respectively. The analytical accuracy for AA quantification ranged from 98.0 % to 105.2 %, and the limit of detection and limit of quantification for AA in coffee were determined to be 1.5 mu g/kg and 5.0 mu g/kg, respectively. In addition, the applicability of the proposed method was assessed through its implementation in the quantification of AA in both roasted and instant coffee. The results prove that the method is simple, rapid, accurate, and sensitive, making it as an excellent option for the detection of AA in coffee.

Astragali Radix, known as a commonly used traditional Chinese medicine, is highly valued for its diverse pharmacologically active compounds. The concentrations of polysaccharides, saponins, and flavonoids serve as critical determinants of product quality. Emerging evidence underscores the pressing need for systematic analysis to elucidate the influence of price-related factors (including growth areas, years, patterns, collected parts, and sampling modes) on the quality of Astragali Radix. In our study, a total of 115 batch samples were collected and the contents of polysaccharides, saponins and flavonoids were determined by spectrophotometry. Comprehensive statistical analyses were performed by the R programming language for three active ingredients across price-influencing factors, and the PCA-based quality evaluation model has been conducted. The findings elucidated the complex interplay among geographic environment, growth years, cultivation modes, and market distribution factors in shaping the quality of Astragali Radix products. Cultivated taproot products from specific geographic regions demonstrated superior polysaccharides accumulation. Shorter-cycle plants exhibited significantly higher polysaccharides levels compared to older plants. Saponins content peaked in imitated-wild cultivation systems. The taproot, traditionally regarded as the superior part, exhibited lower saponin accumulation compared to branches. The content of polysaccharides and flavonoids showed a significant negative correlation. Three active compounds showed the heterogeneity of the accumulation in different plant parts. A significant regional-component interaction emerged in distribution channels analysis. This study provides a data-driven foundation for developing a quality evaluation system for Astragali Radix products. The interpretation of the relationship between various growth and production factors also guides the direction for future research in environmental omics and metabolomics.

The simultaneous determination of arsenic and mercury species in human urine is critical for clinical diagnostics and therapeutic monitoring because it reduces the costs, time, and consumption of samples. This study proposes a method of utilizing high-performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS) for the concurrent analysis of arsenic and mercury species in urine samples. The separation was performed using a Hepu AR 5 μm C18 (250 × 4.6 mm) column, employing a mobile phase composed of 0.1% L-cysteine, 5 mM NH4H2PO4, and 4 mM tetrabutylammonium hydroxide (TBAH). The samples were diluted with water, and matrix interference was reduced through the application of a kinetic energy discrimination (KED) mode. Calibration curves for four arsenic species and three mercury species exhibited strong linearity within the range of 1–20 μg L−1, with correlation coefficients (r) above 0.999. The limits of detection (LOD) ranged from 0.030 to 0.086 μg L−1, while the limits of quantitation (LOQ) were observed to range from 0.10 to 0.29 μg L−1. The spiking recoveries for all species varied from 87.0% to 110.3%, and the intra-day and inter-day relative standard deviations (RSD) were determined to be 1.1–6.0%, and 0.8–9.2%, respectively. These results indicate that the developed method achieves high precision, accuracy, and suitability for clinical applications, offering valuable insights for the diagnosis and treatment of heavy metal exposure.

Although lipophilic shellfish toxins (LSTs) pose a significant threat to the health of seafood consumers, their systematic investigation and risk assessment remain scarce. The goals of this study were as follows: (1) analyze LST levels in commercially available shellfish in Zhejiang province, China, and determine factors influencing LST distribution; (2) assess the acute dietary risk of exposure to LSTs for local consumers during the red tide period; (3) explore potential health risks of LSTs in humans; and (4) study the acute risks of simultaneous dietary exposure to LSTs and paralytic shellfish toxins (PSTs). A total of 546 shellfish samples were collected. LSTs were detected in 89 samples (16.3%) at concentrations below the regulatory limits. Mussels were the main shellfish species contaminated with LSTs. Spatial variations were observed in the yessotoxin group. Acute exposure to LSTs based on multiple scenarios was low. The minimum tolerable exposure durations for LSTs calculated using the mean and the 95th percentile of consumption data were 19.7 and 4.9 years, respectively. Our findings showed that Zhejiang province residents are at a low risk of combined exposure to LSTs and PSTs; however, the risk may be higher for children under 6 years of age in the extreme scenario.

A promising method was established for the determination of nine halobenzoquinones (HBQs) in potable water by membrane solid-phase extraction (MSPE) pretreatment and the liquid chromatography–mass spectrometry (LC-MS) method. A 500 mL water sample was taken for enrichment by the SDB-RPS membrane, which was previously activated by methanol and ultrapure water. The sample was eluted with methanol and re-dissolved with the initial mobile phase after nitrogen blowing. Then, it was detected in negative ion mode using the working curve, and HBQs were quantified by the external standard method. The linearity was satisfactory in the concentration range of 4-1000 ng/L, with correlation coefficients of 0.9963~0.9994. The recoveries were 73.5~126.6% at three spiked levels, with relative standard deviations (RSDs) of 6.8~15.5%. The limits of detection (LOD, S/N = 3) values were 0.1~0.7 ng/L. The results demonstrate that the MSPE-LC-MS method is reliable, rapid, and sensitive for the simultaneous analysis of nine HBPs in potable water.

OBJECTIVE:To establishe an analysis and identification method for 2-methylisoborneol(2-MIB) and geosmin(GSM) in water using purge and trap-gas chromatography-mass spectrometry.METHODS:The samples were enriched and analyzed using a purge and trap system, followed by the separation on a DB-624(30 m×0.25 mm, 1.4 μm) chromatographic column. Quantification was performed using gas chromatography-mass spectrometry with the selected ion monitoring and internal standard calibration.RESULTS:The calibration curves for 2-MIB and GSM showed an excellent linearity in the range of 1 to 100 ng/L with R~2 values greater than 0.999. The detection limit and quantification limit for both 2-MIB and GSM were 0.33 ng/L and 1.0 ng/L, respectively. Spike recovery experiments were further carried on the source water and drinking water at three concentration levels. It showed that the average recoveries were from 82.0% to 111.0% for 2-MIB while 84.0% to 110% for GSM. Additionally, the test precision of 2-MIB and GSM ranged from 1.9% to 7.3% and 1.9% to 5.0%(n=6), respectively. The analysis of multiple samples including the local source water, treated water and distribution network water confirmed the existence of 2-MIB and GSM.CONCLUSION:Compared to the national standard(GB/T 5750.8-2023), the proposed method enables fully automated sample introduction and analysis without the extra pre-treatment. It provides the advantages of simplicity, good repeatability and high accuracy.

This study aims to examine the hazards of zearalenone (ZEN) to humans and assess the risk of dietary exposure to ZEN, particularly in relation to precocious puberty in children from the Zhejiang Province. The test results from five types of food from the Zhejiang Province show that corn oil has the highest detection rate of 87.82%. The levels of ZEN do not exceed the existing safety standards in any sample investigated in this study. According to the data from the Food Consumption Survey of Zhejiang Province residents, rice is the primary source of ZEN exposure, accounting for 55.85% of total exposure among all age groups. Based on the 50th exposure percentile, it would take 6.25 years of rice consumption to reach 1 year of safe ZEN exposure. Overall, the majority of the residents in the Zhejiang Province have a low risk of exposure to ZEN. In an extreme case (based on the 95th exposure percentile), the total ZEN exposure from the studied foods with respect to children aged ≤6 years and 7–12 years is 0.38 μg/kg b.w. and 0.26 μg/kg b.w., respectively—both exceeding the safety limit of 0.25 μg/kg b.w. set by the European Food Safety Authority, indicating a potential risk of exposure. Precocious puberty assessments show that ZEN exposure levels in children in the Zhejiang Province are significantly lower than those associated with precocious puberty; thus, precocious puberty is unlikely to occur in this area. Given ZEN’s estrogenic effect, it is necessary to monitor the level of ZEN in different food items, revise the relevant standards as needed, and focus on exposure to ZEN in younger age groups.