Objective:To establish a automatic headspace gas chromatography-mass spectrometry (HS/GC-MS) method for the determination of 14 volatile organic compounds in urine.Methods:In September 2022, 10 ml urine sample was taken into a 20 ml headspace bottle, balanced for 30 min at 65 ℃, and then detected by HS/GC-MS and quantified by external standard method.Results:The 14 volatile organic compounds showed good linearity at 0.2-8.0 μg/L and 0.1-4.0 μg/L, with correlation coefficients ranging from 0.9956-0.9999. The recoveries were 79.8%-113.1% with relative standard deviations 0.05%-0.27% when three different concentration levels were added. Detection limit was 0.03-0.05 μg/L.Conclusion:The method is simple and convenient, and the recovery and precision meet the requirements. It can be used for the determination of common volatile organic compounds in urine.

Objective:To establish a automatic headspace gas chromatography-mass spectrometry (HS/GC-MS) method for the determination of 14 volatile organic compounds in urine.Methods:In September 2022, 10 ml urine sample was taken into a 20 ml headspace bottle, balanced for 30 min at 65 ℃, and then detected by HS/GC-MS and quantified by external standard method.Results:The 14 volatile organic compounds showed good linearity at 0.2-8.0 μg/L and 0.1-4.0 μg/L, with correlation coefficients ranging from 0.9956-0.9999. The recoveries were 79.8%-113.1% with relative standard deviations 0.05%-0.27% when three different concentration levels were added. Detection limit was 0.03-0.05 μg/L.Conclusion:The method is simple and convenient, and the recovery and precision meet the requirements. It can be used for the determination of common volatile organic compounds in urine.

A foodborne poisoning incident occurred in a street， Ouhai District， Wenzhou City， Zhejiang Province on May 9， 2023， which was caused by the accidental consumption of medicinal liquor containing aconitum alkaloids. Three individuals drank homemade aconite-containing medicinal liquor and were subsequently poisoned， of which two cases were severe， and one case was mild. All three patients exhibited symptoms such as numbness in the mouth， tongue and limbs， dizziness， fatigue， nausea， vomiting， and blurred vision. Two of them successively entered a state of shock and coma， with an incubation period of approximately 30 minutes. Among seven samples of suspected homemade medicinal liquor， one sample tested positive simultaneously for aconitine， neaconitine， hypaconitine， and benzoylaconitine， with concentrations of 62.3 mg·L^-1， 2.6 mg·L^-1， 17.7 mg·L^-1， and 31.6 mg·L^-1， respectively. Four kinds of aconite alkaloids were detected in all the urine， blood， and vomit samples from the patients， and the most toxic aconitine was detected at levels of 1.5 μg·L^-1， 5.9 μg·L^-1， and 26.2 μg·L^-1， respectively. Based on the field epidemiological investigation， combined with clinical manifestations and laboratory test results， it was determined that this incident was a case of food poisoning caused by the accidental consumption of medicinal liquor containing aconite. Due to timely rescue and proper treatment measures， all poisoned patients have recovered， with no fatalities. It is suggested that relevant authorities should strengthen the regulation of the processing and sale of aconite herbs and promote the awareness of food safety.

ObjectiveTo establish an ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS)-internal standard method for the simultaneous determination of 59 antibiotics, including quinolones, sulfonamides, tetracyclines, macrolides and nitroimidazole in bean sprouts. MethodsThe internal standard compounds and 5.0 mL of acetonitrile containing 0.1% formic acid were added into 5.0 g of the sample, and then extracted by ultrasonication. The extracted supernatant was filtered by 0.22 µm membrane and then injected into 1.0 µL of the sample directly. Methanol containing 0.1% formic acid and 2.0 mmol·L^-1 ammonium formate containing 0.1% formic acid were taken as the mobile phases to conduct gradient elution. The separation was achieved on an ACQUITY PREMIER BEH C₁₈ column. The separated analytes were detected by the electrospray ionization (ESI) in multiple reaction monitoring (MRM) mode, and quantified by internal standard method. ResultsThe 59 kinds of antibiotics in bean sprouts had a good linear relationship in the range of 10 μg·kg^-1 to 1 000 μg·kg^-1. The limits of detection (LODs) and the limits of quantification (LOQs) of the method for soybean sprouts ranged from 0.1 μg·kg^-1 to 3.0 μg·kg^-1 and 0.4 μg·kg^-1 to 10.0 μg·kg^-1, respectively. While, the LODs and LOQs of the method for mung bean sprouts ranged from 0.1 μg·kg^-1 to 2.0 μg·kg^-1 and 0.4 μg·kg^-1 to 7.0 μg·kg^-1, respectively. The average recoveries of the 59 kinds of antibiotics at four levels (10、50、200、800 μg·kg^-1) in soybean sprouts were 82.1%‒122.3%, with the relative standard deviations (RSDs) of 1.2%‒15.4% (n=6). However, the average recoveries of the 59 kinds of antibiotics in mung bean sprouts were 87.3%‒119.1%, with the RSDs of 0.9%‒15.0% (n=6). ConclusionThe method is rapid, highly sensitive and accurate, which can be used for rapid screening of quinolones, sulfonamides, tetracyclines, macrolides, and nitroimidazole antibiotics in large quantities of bean sprouts.

ObjectiveTo investigate the status and dietary intake risk of pesticide residues in fruits and vegetables sold in Wenzhou, Zhejiang Province from 2020 to 2023, so as to provide a scientific basis for the regulation and management of pesticide in the future. MethodsIn accordance with the requirements and methods specified in the “National Food Contamination and Hazardous Factor Risk Monitoring Work Manual” and the current corresponding national food inspection standards for various foods, a total of 807 samples of vegetables and fruits from various counties and districts of Wenzhou City were collected for testing and analysis. Eventually, 23 types of pesticides with a detection rate greater than 5% and those exceeding the standard were selected for dietary intake risk assessment. ResultsFrom 2020 to 2023, the overall detection rate of pesticide residues in fruits and vegetables monitored in Wenzhou was 71.62%, with an overall exceedance rate of 5.27%. From the results of the monitoring of pesticide residues in fruits and vegetables, fresh legume vegetables had the highest detection rate of 90.00%. Among the six major categories of pesticides monitored, fungicides in vegetables and fruits had the highest detection rates of 68.18% and 85.03%, respectively. The highest exceedance rate in vegetables was organophosphorus pesticides, accounting for 2.85%, while in fruits, neonicotinoid pesticides had the highest exceedance rate of 3.21%. From the perspective of sampling time, the peak detection rate of pesticide residues in fruits and vegetables in Wenzhou occurred in June and October. The index of food safety (IFS) of the 23 pesticides with a detection rate higher than 5% ranged from 0.000 7 to 0.694 2 based on the 95% monitoring value of pesticide residues, which were all less than 1. Calculated at maximum content, the IFS values of dithiocarbamate (calculated by CS₂), chlorothalonil and propiconazole were all greater than 1, indicating that the maximum detection values of the three pesticides exceeded the acceptable safety risk. The risk level of acute dietary intake of the 23 pesticides ranged from 1.26% to 52.65%. ConclusionThe overall situation of pesticide residues in fruits and vegetables sold in Wenzhou from 2020 to 2023 is favourable, but the exceedance rate of pesticide in some fruits and vegetables is high. Special attention should be paid to the pesticide residues of fungicides, neonicotinoid insecticides and organophosphorus pesticides in fresh legume vegetables, bulb vegetables and some fruits sold in Wenzhou, such as acetamiprid in bayberry and cowpea, dimethomorph in strawberry, chlorpyrifos in leek, etc., and monitoring of pesticide residues in food need to be strengthened.