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Objective: To investigate the specificity of endogenous metabolic profile in plasma of patients with occupational acute methyl acetate poisoning using non-targeted metabolomics. Methods: A total of six patients with occupational acute methyl acetate poisoning were selected as the poisoning group, while 10 healthy workers without occupational exposure history of chemical hazards in the same industry were selected as the control group using the judgment sampling method. Metabolites in patient plasma of the two groups were detected using ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry, and non-targeted metabolomics analysis was performed. Principal component analysis and partial least squares discriminant analysis were used to identify differential metabolites and analyze their metabolic pathways. Results: There were significant differences in metabolite profiles in patient plasma between poisoning group and control group. A total of 195 differentially expressed metabolites were screened in plasma of patients in poisoning group, including 119 upregulated and 76 downregulated metabolites. Lipid substances (lipids and lipid-like molecules) accounted for the highest proportion (21.5%). The differential metabolites of poisoning group were related to folate biosynthesis, amino acid metabolism, pyrimidine metabolism, sphingolipid biosynthesis and other metabolic pathways in plasma compared with the control group (all P<0.05). Conclusion: Occupational acute methyl acetate poisoning affects metabolism of the body. The folic acid biosynthesis, amino acid and lipid metabolism and other pathways may be involved in the occurrence and development of poisoning.
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{L-End}Objective To establish a method for the simultaneous determination of dimethyltin (DMT), trimethyltin (TMT), diethyltin (DET), and triethyltin (TET) in human whole blood using high performance liquid chromatography-inductively coupled plasma-mass spectrometry (ICP-MS). {L-End}Methods The 1.0 mL of blood was added with 4.0 mL 65% aqueous solution (containing 6% acetic acid), extracted and separated by C4 column (150 mm×3 mm×3 μm) using a mobile phase of methanol and 4% acetic acid aqueous solution (containing 0.25 mmol/L tropolone) at a volume ratio of 35∶65, and detected by ICP-MS. {L-End}Results The linear range of DMT, TMT, DET, and TET was 30.60-550.80, 29.00-522.00, 46.10-829.80, and 34.05-612.90 μg/L, respectively. All correlation coefficients were 0.999. The detection limit of DMT, TMT, DET and TET was 21.40, 20.30, 32.27 and 23.80 μg/L, respectively. The recovery rate was 81.9%-104.9%. The within-run and between-run relative standard deviation was 1.6%-6.9% and 0.1%-10.0%, respectively. The samples can be stored at -20 ℃ and 4 ℃ for at least three days. {L-End}Conclusion This method can be used for trace analysis of DMT, TMT, DET, and TET in whole blood.
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OBJECTIVE: To establish a method for detecting thiocyanate in human urine by high performance liquid chromatography( HPLC) with 2,3,4,5,6-pentafluorobenzyl bromide as precolumn derivatization reagent.METHODS: Thiocyanate in human urine was derived with 2,3,4,5,6-pentafluorobenzyl bromide, and separated by poroshell 120EC-C18 column with acetonitrile:deionized water( 60:40,V/V) as mobile phase.detected by HPLC,Liquid chromatography-UV detector was used for determination.The wavelength was 212.00 nm.RESULTS: Good linearity was obtained in the range of 0.05-10.32 mg/L with the correlation coefficient of 0.999.The detection limit was 6.31 μg/L and the minimum detection concentration was 63.10 μg/L( 0.1 mL urine).The recovery rate was 95.1%-102.9%.The within-run relative standard deviation( RSD) and the between-run RSD were 0.9%-1.0% and 0.9%-2.1%,respectively.The urine samples could be stored at 4 ℃ for 7 days.CONCLUSION: This method has high sensitivity,good specificity and sample preparation,which can be used for detecting urine thiocyanate in occupational population.
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OBJECTIVE: To evaluate the bacteriostatic effect of ε-polylysine( ε-PL) on four common putrefactive bacteria including Staphylococcus aureus,Enterococcus faecalis,Pseudomonas aeruginosa,and E. coli and its effect on urine lead level. METHODS: Broth dilution method was used for the determination of the minimum inhibitory concentration( MIC) ofε-PL on the four kinds of putrefactive bacteria; the inhibitory effects of ε-PL with final mass concentration of 40. 000 mg / L on the urine sample were observed; graphite furnace atomic absorption spectrometry was used for determining the lead level in the 40. 000 mg / L( mass concentration) ε-PL solution and the urine lead level in normal healthy groups; the bacteriostatic effects of ε-PL and nitric acid were compared. RESULTS: The MIC of ε-PL on Staphylococcus aureus,Enterococcus faecalis,Pseudomonas aeruginosa,and E. coli was 40. 000 mg / L. There was no bacterial growth in the urine sample with40. 000 mg / L( mass concentration) ε-PL when urine was kept at room temperature for 24 hours to 15 days. The lead level was < 2. 0 μg / L in the 40. 000 mg / L( mass concentration) ε-PL solution. When the ε-PL with final mass concentration of 40. 000 mg / L and the nitric acid with a volume fraction of 1. 0% were respectively used as the antiseptics,the descending rates of the lead levels in the urine samples were similar,and after the urine sample was preserved for 15 days,the descending rates of the urine lead were both smaller than 10. 0% after be stored for 15 days. CONCLUSION: ε-PL can substitute nitric acid as a new natural preservative for preservation of samples for urine lead determination.