Environmental Monitoring ; methods ; Gas Chromatography-Mass Spectrometry ; methods ; Humans ; Industry ; Volatile Organic Compounds ; analysis

Objective: To establish a solvent desorption gas chromatographic method for determination of Sevoflurane, Isoflurane and Enflurane in the air of the Workplace. Methods: Sevoflurane, Isoflurane and Enflurane were collected with activated carbon tube and desorbed with dichloromethane, separated with DB-1 capillary columns, and then detected with flame ionization detector. Results: The linearity ranges were 1.9-304.8 μg/ml for Sevoflurane, 2.1-300.4 μg/ml for Isoflurane and 1.7-305.2 μg/ml for Enflurane, The correlation coefficient was both >0.999. Their limits of detection were 0.6 μg/ml, 0.6 μg/ml and 0.5 μg/ml, and Their limits of quatification were 1.9 μg/ml, 2.1 μg/ml and 1.7 μg/ml, and their minimum detectable concentrations were 0.1、0.2 and 0.1 mg/m³ per 4.5 L of air. Their relative standard deviations (RSD) were 2.5%-3.0%, 2.3%-3.1% and 2.2%-3.0%. The average desorption efficiencies were 101.1%-103.3%, 100.7%-102.7% and 101.0%-102.9%. The sampling efficiency was both 100%. The breakthrough volume of 100 mg actived carbon was 3.7 mg, 3.4 mg and 3.4 mg. Sevoflurane, Isoflurane and Enflurane in activated carbon tube could be kept at least 10 days at room temperature without significant losses. Conclusion The method shows lower detection limit, high accuracy and precision. It is feasible for determination of Sevoflurane, Isoflurane and Enflurane in the air of workplace.

Objective To establish the method of atomic fluorescence spectrometry (AFS) after alkali fusion for determination of tin dioxide in workplace air.Methods Tin dioxide in workplace air was collected with microporous membrane,directly digested by alkali fusion with solid sodium hydroxide heated by electric furnace,and determined by AFS.Results The linear range of tin dioxide (as Sn) determined by AFS was 1.5～ 100 μg/L (excluding zero),and the correlation coefficient was 0.9993.The detection limit of this method was 0.5 μg/L,the lower limit of quantification was 1.5 μg/L,and the minimum detectable concentration was 0.05 mg/m3 (the volume of the air sample was 75 L).The relative standard deviation was 1.94％～3.55％,and the average recovery of standard addition was 95.0％～96.0％.Conclusion The method of AFS after alkali fusion for determination of tin dioxide in workplace air is proved to be simple,rapid,sensitive,and accurate,with complete digestion.

Objective To establish the method of atomic fluorescence spectrometry (AFS) after alkali fusion for determination of tin dioxide in workplace air.Methods Tin dioxide in workplace air was collected with microporous membrane,directly digested by alkali fusion with solid sodium hydroxide heated by electric furnace,and determined by AFS.Results The linear range of tin dioxide (as Sn) determined by AFS was 1.5～ 100 μg/L (excluding zero),and the correlation coefficient was 0.9993.The detection limit of this method was 0.5 μg/L,the lower limit of quantification was 1.5 μg/L,and the minimum detectable concentration was 0.05 mg/m3 (the volume of the air sample was 75 L).The relative standard deviation was 1.94％～3.55％,and the average recovery of standard addition was 95.0％～96.0％.Conclusion The method of AFS after alkali fusion for determination of tin dioxide in workplace air is proved to be simple,rapid,sensitive,and accurate,with complete digestion.

Objective:To establish a method for determining mercury in blood with direct mercury analyzer.Methods:After the whole blood sample was extracted by solvent and removed by nitric acid, it was then measured by direct mercury analyzer.Results:After optimizing the conditions of the instrument, the linear range was 0.3-60.0 μg/L and the curve correlation coefficient was higher than 0.999. The lower limit of quantitations was 0.3 μg/L and the minimum quantitative concentration was 3.0 μg/L. The recovery and relative standard deviations ( RSD) was 95.2%-97.6% and 1.4%-3.3%. Conclusion:The method is stable, reliable, easy to operate and has high sensitive. It can be used to determine mercury in blood.

Objective:To establish a method for determining mercury in blood with direct mercury analyzer.Methods:After the whole blood sample was extracted by solvent and removed by nitric acid, it was then measured by direct mercury analyzer.Results:After optimizing the conditions of the instrument, the linear range was 0.3-60.0 μg/L and the curve correlation coefficient was higher than 0.999. The lower limit of quantitations was 0.3 μg/L and the minimum quantitative concentration was 3.0 μg/L. The recovery and relative standard deviations ( RSD) was 95.2%-97.6% and 1.4%-3.3%. Conclusion:The method is stable, reliable, easy to operate and has high sensitive. It can be used to determine mercury in blood.

Objective: To establish a method for determination of acetone, dichloromethane, hexane, 1, 1, 1-trichloroethane, 1, 2-dichloroethane, benzene, toluene, ethylbenzene etc organic compounds in urine by headspace gas chromatography-mass spectrometry (GC-MS) . Methods: Headspace gases of urine samples were injected into GC and determined by mass. Results: Determination of urine components were in a good linear range in their concentration range of this method. The correlation coefficients were between 0.996 and 1.000 with the detection limits between 0.1 μg/L and 4.5 μg/L, the precisions were between 1.3% and 4.6%, the recovery rates were between 86.2% and 97.4%. Conclusion This method has the advantages of low detection limits, high accuracy, high precision and simple pretreatment, which is suitable for the determination of the content of various volatile organic compounds in urine.

Objective: To establish a method for the determination of manganese in urine by graphite furnace atomic absorption spectrometry (AAS) without the use of matrix modifier. Methods: The urine samples were 5 times diluted with 1% nitric acid then directly determined by AAS. Zeeman was used for background correction. Results: The linear range for determination of manganese in urine was 5~60 μg/L (urine) . The correlation coefficient was greater than 0.995 with the detection limit of 1.5 μg/L and with the lower limit of quantification of 5.0 μg/L. The relative standard deviations (RSDs) of within-run precision was between 1.1%~4.3%, the RSDs of between-run precision was between 3.3%~7.0%. The average recovery was 102.6%. The samples can be stored for 14 days at room temperature, 4℃, -8 ℃ and -35 ℃. Conclusion The method is feasible for determination of manganese in urine.

Objective:To establish a LC-MS/MS method for determination of paraquat and diquat in plasma and urine samples.Methods:Plasma is precipitated by acetonitrile then diluent with phosphate buffer (pH=7) , urine is diluent with phosphate buffer (pH=7) , then diluent samples extracted with Oasis WCX solid-phase extraction column. Samples were analyzed using LC-MS/MS in multiple reaction monitoring (MRM) mode. The analytical column was XBridge?BEH-HILIC (100 mm×2.1 mm×2.5 μm) and the mobile phase were 100 mmol ammonium formate add 0.5% formic acid and acetonitrile. Paraquat was quantified by internal standard method and diquat by external standard method.Results:The calibration curves of paraquat and diquat were linear in the concentration range of 10.0~120.0 μg/L, the correlation coefficient (r) were 0.9985~0.9994. The limit of detection of paraquat in plasma and urine were 1.98 μg/L and 1.00 μg/L, respectively, the recovery rate were 100.2%~107.3%, the RSD were 1.6%~3.3%. The limit of detection of diquat in plasma and urine were 1.80 μg/L and 2.77 μg/L, respectively, the recovery rate were 85.3%~93.1%, the RSD were 1.8%~5.5%. Conclusion:This method is sensitive and accurate, and can simultaneously determine paraquat and diquat in plasma and urine.

Objective:To establish a LC-MS/MS method for determination of paraquat and diquat in plasma and urine samples.Methods:Plasma is precipitated by acetonitrile then diluent with phosphate buffer (pH=7) , urine is diluent with phosphate buffer (pH=7) , then diluent samples extracted with Oasis WCX solid-phase extraction column. Samples were analyzed using LC-MS/MS in multiple reaction monitoring (MRM) mode. The analytical column was XBridge?BEH-HILIC (100 mm×2.1 mm×2.5 μm) and the mobile phase were 100 mmol ammonium formate add 0.5% formic acid and acetonitrile. Paraquat was quantified by internal standard method and diquat by external standard method.Results:The calibration curves of paraquat and diquat were linear in the concentration range of 10.0~120.0 μg/L, the correlation coefficient (r) were 0.9985~0.9994. The limit of detection of paraquat in plasma and urine were 1.98 μg/L and 1.00 μg/L, respectively, the recovery rate were 100.2%~107.3%, the RSD were 1.6%~3.3%. The limit of detection of diquat in plasma and urine were 1.80 μg/L and 2.77 μg/L, respectively, the recovery rate were 85.3%~93.1%, the RSD were 1.8%~5.5%. Conclusion:This method is sensitive and accurate, and can simultaneously determine paraquat and diquat in plasma and urine.