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OBJECTIVE To develop a simple, fast and sensitive analytical method based on isotope dilution-headspace gas chromatography-mass spectrometry for the determination of 1, 4-dioxane residue in the aerosol cosmetics. METHODS Sample was successive weighed and dissolved in 1, 3-dimehyl-2-imidazolidinone(DMI)solvent and isotope internal standard was added. Then transfered to a 20 mL headspace vial. The headspace vial was sealed and extracted 15 min by ultrasonic-assisted extraction. After separated by HP-5 MS fused silica capillary column(30 m×25 mm, 0. 25 μm), the compound was analyzed by gas chromatography-mass spectrometry in selected ion monitoring mode(GC-MS-SIM) and quantified by internal standard method. RESULTS There were good linear correlations with R~2 no less than 0. 999 in the range of 1. 0-100 mg/kg. The limit of detection(LOD) of this method was 0. 3 mg/kg. At 0. 3, 1. 0, 5. 0 and 30 mg/kg four added concentration, recovery for five kinds of aerosol cosmetic were all between 91. 4% and 104. 2%. The relative standard deviations(RSDs) were 1. 5%-6. 3% and 1. 7%-6. 4%(n=6), respectively. CONCLUSION The developed method has proved convenient, time-saving, accurate and sensitive and suited for determination 1, 4-dioxane in aerosol cosmetic.OBJECTIVE To develop a method for the determination of 11 perfluorinated compounds(PFCs) in drinking water by solid phase extraction-ultra performance liquid chromatography tandem mass spectrometry(UPLC-MS/MS). METHODS The target analytes in water samples were concentrated and purified by Oasis WAX SPE column and eluted with 5 mL methanol and 7 mL 0. 1% ammonia-methanol solution. The eluent was blown to near dryness under a nitrogen gas, diluting with methanol water solution(3∶7, V/V) to 1 mL for analysis by UPLC-MS/MS. RESULTS There were good liner relationship in the range of 0. 5-50 μg/L. The detection limit and the limit of quantitation were 0. 03-0. 7 ng/L and 0. 5-3. 0 ng/L, respectively. The recoveries of 11 PFCs at three different spiked concentrations were 90. 0%-122. 3%, 87. 1%-130. 0% and 80. 0%-113. 7%, respectively, and the relative standard deviation were 1. 95%-8. 59%, 1. 27%-9. 08% and 2. 17%-10. 51%(n=6), respectively. CONCLUSION This method has wide linear range, low detection limit and limit of quantitation, applicable for simultaneous analysis and monitorting of 11 PFCs in drinking water.OBJECTIVE To establish a method for determination of thiram, propineb and metiram in mushroom samples by gas chromatography-mass spectrometry(GC-MS). METHODS Insoluble heavy metal salts were converted into water-soluble sodium salts by alkaline buffer with strong chelating agents. Dithiocarbamates can be converted into different methyl ester compounds with ion pair methylation. The GC separation was performed on a DB-5 MS capillary column(30 m×0. 25 mm, 0. 25 μm). The pesticides were detected by GC-MS with selective ion monitoring(SIM) and quantified by external standard of working curve method. Methodsological verification was carried out based on optimized sample pretreatment and GC-MS condition. RESULTS The concentrations of dithiocarbamates exhibited a good linear relationship with GC-MS within a certain range. The limits of detection of thiram, propineb and metiram were 0. 01, 0. 05 and 0. 05 mg/kg, respectively. Furthermore, the average recoveries were from 76. 98% to 93. 52%, and the maximum relative standard deviation was 11. 54%(n=6). CONCLUSION This method is simple, sensitive, accurate and reliable. All the indices meet the requirements of pesticide residue detection.OBJECTIVE To establish a method for simultaneous determination of 20 flavonoid compounds from honey samples using solid phase extraction coupled with ultra-performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS), which was applied to study the difference of flavonoid compounds in honey samples from different botanical origins. METHODS The honey samples were extracted with ultra-water solution by ultrasound, and purified with an Oasis MAX column, and then separated on a Waters ACQUITY UPLC HSS T3(2. 1 mm×100 mm, 1. 8 μm) and eluted with the mobile phase consisted of 0. 1% formic acid in water and acetonitrile in a gradient program, and analyzed by mass spectrometry equipped with an electrospray ionization source, operating in the positive or negative ionization modes, and performed in the multiple reaction monitoring using external standards. RESULTS Twenty flavonoid compounds showed good linearity with coefficients higher than 0. 9969; The recoveries of spiked honey samples in the range of 76. ientific data and application basis for quality analysis.OBJECTIVE To investigate the effects of lycopene on metabolism of glycolipid and inflammation in rats with non-alcoholic fatty liver disease. METHODS According to body weight, sixty male Sprague-Dawley rats were randomly divided into control group, non-alcoholic fatty liver model group, 20, 60 mg/kg lycopene intervention groups, with 15 rats in each group. The control group was fed normal diet, and the other 3 groups were fed high-fat and high-fructose diet for 4 weeks to establish the model of non-alcoholic fatty liver disease. After modeling, the intervention groups were fed lycopene of different doses by gavage. After 8 weeks of continuous feeding, the rats were sacrificed, the body weight and liver weight were weighed, and the liver index was calculated. Hematoxylin-eosin staining was used to observe the morphological changes of liver tissue. Serum was collected, fasting blood glucose(FBG), fasting insulin(INS), and insulin resistance index(HOMA-IR) were calculated; Liver function indicators alanine amino. CONCLUSION Lycopene can improve non-alcoholic fatty liver disease by regulating glycolipid metabolism and reducing levels of inflammatory cytokines in rats.OBJECTIVE To investigate the effects of resveratrol combined with soy isoflavones on avoidance memory, number of neuron-specific nuclear protein(NeuN) positive cells and expressions of glucose transporter(GLUT)1 and GLUT3 in hippocampus of aging model rats. METHODS A total of 60 female SD rats were randomly divided into 6 groups including sham control group, aging model group, 80 mg/kg resveratrol group, 160 mg/kg soy isoflavones group, 80 mg/kg resveratrol +160 mg/kg soy isoflavones group, 0. 8 mg/kg estradiol valerate group. The aging model rats was induced by ovariectomy combined with intraperitoneal injection of 100 mg/kg D-galactose. Intragastric administration was performed once a day for 12 weeks. The avoidance task was measured by the shuttle box test. The NeuN expression were measured by the immunofluorescence. The genes and proteins expression of GLUT1 and GLUT3 in rat hippocampus were detected by real-time PCR and Western blot, respectively. RESULTS Compared with the sham control group, the avoidance latency in the aging model group was prolonged, and the active avoidance response rate and the total avoidance response rate were decreased. The number of NeuN positive cells decreased and the expression levels of GLUT1 and GLUT3 genes and proteins were decreased(P0. 05). CONCLUSION Resveratrol and soy isoflavones alone and in combination can improve the learning and memory ability of aging rat models. The mechanism may be related to up-regulating the expression of GLUT1 and GLUT3 genes and proteins in the hippocampus, promoting the transmembrane transport of glucose and reducing neuronal loss.OBJECTIVE To understand the exposure levels of polycyclic aromatic hydrocarbons(PAHs) and the expression of interleukin-2(IL-2), interferon-γ(IFN-γ), interleukin-4(IL-4), interleukin-10(IL-10) in peripheral blood of coke oven workers exposed to coke oven emissions(COEs). The other purpose of this study was to understand the performance of IFN-γ and IL-10 epigenetic mechanisms in COEs exposure damage. METHODS The 85 workers exposed to COEs in a coking plant were randomly selected as the exposure group. The 47 workers who were exposed to non-COEs in the coking plant were used as the control group. The morning urine of the exposure group and the control group were subjected to detection of 1-OHPyr levels with alkaline hydrolysis High-performance liquid chromatography fluorescence, urine creatinine correction. The peripheral venous blood were subjected to detection of the expression of IL-2, IFN-γ, IL-4 and IL-10 with enzyme-linked immunosorbent assay. And methylation levels of IFN-γ and IL-10 were analyzed by tit in the furnace. The difference was statistically significant. The IL-10 CpG-11, CpG-15 and mean methylation rates in the exposed group were lower than those in the control group, and the differences were statistically significant. The methylation rate of IFN-γ CpG-5 in the exposed group was higher than that in the control group, and the difference was statistically significant. The urine 1-OHPyr content of coke oven workers was negatively correlated with TH1/TH2 ratio and IFN-γ expression level, and positively correlated with IL-4 and IL-10 levels. The IL-10 CpG-11, CpG-15 methylation rate decreased with increasing urine 1-OHPyr concentration. CONCLUSION The side and top of the furnace worker exposed to COEs were the key targets for occupational health. The exposure of coke oven workers to COEs affected the expression of immunoregulatory cytokines. The exposure of COEs caused the change of IL-10 methylation rate.OBJECTIVE To investigate the contamination levels of sodium nitrite in cooked meat from parts of China during 2012-2015. METHODS The samples were detected in accordance with the national standardization method, and were determined by the GB 2760-2014. RESULTS The average sodium nitrite in cooked meat was 9. 7 mg/kg with the content range from not detected to 85. 3 mg/kg, and its exceeding standard rate was 4. 8%(922/19360). The average sodium nitrite in visceral products was 16. 6 mg/kg, which was the highest in all kinds of cooked meat. The exceeding standard rate of farmers’ market was significantly higher than that of other sampling links. The exceeding standard rate of bulk samples was 5. 8 times of the stereotyped packaging. The exceeding standard rate was downgrade year by year. The main problem was the bulk sauce-stewed meat product in the farm product market which the exceeding standard rate was 9. 5%(327/3461). CONCLUSION A four-year successive observation shows that the quality of cooked meat with sodium nitrite is improved. But the problem is focused on the bulk. The risk of nitrite in cooked meat is lower.OBJECTIVE To assess the intake of caffeine from snacks among children and adolescents aged 6-17 years in Beijing City. METHODS A multi-stage stratified cluster random sampling method was adopted to obtain the consumption status of caffeine-containing snacks among 881 school-age children and adolescents in Chaoyang, Changping and Yanqing Districts through a 3 d 24 h continuous questionnaire survey between October 2016 and February 2017, and the caffeine content in snacks was obtained through literature retrieval and laboratory detection. RESULTS The proportion of caffeinated snacks consumers among children and adolescents aged 6-17 years in Beijing was 42. 45%(374/881). The average daily caffeine intake of the whole population was 9. 19 mg, with a median of 0 and a P95 of 41. 38 mg. read more The average daily caffeine intake of consumers was 21. 66 mg, with a median of 11. 03 mg and 76. 99 mg of P95. About 1. 60%(6/374) of individuals exceeded the daily safe intake level and there were statistically significant differences in caffeine intake between different ages, genders, grades and groups with and without tea drinking habits after weight was taken into account.