ABSTRACT
Objective To establish a rapid qualitative analysis method for volatile organic components in chemicals. Methods Headspace gas chromatography-mass spectrometry was used to qualitatively determine 19 volatile organic components, including benzene, 1,2-dichloroethane, and n-hexane, in chemicals. Different sample amounts, heating temperatures, heating times, and sample volumes were analyzed to assess their effects on detection results and optimize sampling conditions. Results Based on the set chromatography, the optimal sampling process of this method was as follows： 5.0 g sample in a 20.0 mL headspace bottle, incubated at 40 ℃ for 30 minutes in a constant-temperature drying incubator, and a 1.00 mL headspace gas injection. The within-run and between-run relative standard deviations of all components ranged from 0.00% to 21.05% and 0.00% to 33.33%, respectively. The samples stored in sealed glass containers were stable at room temperature for at least 60 days. Conclusion This method offers simplicity, good reproducibility, and stability, making it suitable for rapid qualitative analysis of volatile organic components in chemicals.
ABSTRACT
OBJECTIVE: To establish a headspace gas chromatography-mass spectrometry method for the determination of 14 chlorinated hydrocarbons in urine. METHODS: The urine sample 4.00 mL and anhydrous sodium sulfate 3.00 g were added into a 10.00 mL headspace bottle, then the headspace bottle was maintained at 70 ℃ for 40.0 min. After headspace pretreatment, 14 chlorinated hydrocarbons in headspace air were separated in the DB-5 MS capillary column of the gas chromatography and detected by mass spectrometer. RESULTS: There was a good linear relationship of 14 chlorinated hydrocarbons in urine in the range of 0.62-1 630.00 μg/L. The linear correlation coefficient was greater than 0.999 0.The minimum detectable concentration was 0.19-0.43 μg/L and the minimum quantitative concentration was 0.62-1.44 μg/L. The average recovery rate was 89.8%-107.1%. The within-run relative standard deviation(RSD) was 4.0%-8.5% and the between-run RSD was 6.3%-9.1%. Urine samples can be stored at 4 ℃ or-8 ℃ for 3 days and below-20 ℃ for 7 days. CONCLUSION: This method is rapid, simple, sensitive, accurate and has little interference,which can be used as a method for detecting 14 kinds of chlorinated hydrocarbons in urine samples of patients with occupational poisoning.
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OBJECTIVE: To establish a method for detecting dichloromethane,trichloromethane and 1,2-dichloroethane in blood by gas chromatography-mass spectrometry. METHODS: Using static headspace analysis, three halogenated hydrocarbons in blood samples were separated by DB-5 MS elastic capillary column and detected by gas chromatographymass spectrometry. RESULTS: There was a good linear relationship in the selected range of dichloromethane,trichloromethane and 1,2-dichloroethane in blood. The linear correlation coefficient was greater than 0. 999 8. The detection limit and the lower limit of quantitation was 0. 19-0. 28 and 0. 64-0. 93 μg/L,respectively. The average recovery rate was 95. 1%-106. 6%. The within-run and between-run relative standard deviation was 2. 9%-4. 9% and 5. 0%-7. 0%,respectively. The samples could be preserved at room temperature or 4 ℃ for 3 days and at-8 ℃ or below for7 days. CONCLUSION: With the features of high sensitivity,precision,accuracy,easy operation and less interference,this method is suitable for detecting dichloromethane,trichloromethane and 1,2-dichloroethane in the blood.
ABSTRACT
Oceanic carbon monoxide(CO) has been of biogeochemical interest due to its significant role in global carbon cycle and the greenhouse effect. A headspace method coupled with ta3000 trace gas analyzer system for the determination of CO in seawater was developed. The effects of temperature, equilibrium time and water/gas volume ratio on the sensitivity of headspace analysis were studied in detail. The results showed that CO concentrations in seawater were measured successfully by the 50-mL glass-only syringes with a water/gas volume ratio of 44∶ 6 and an equilibrium time of 5 min at 20 ℃ room temperature. Under the optimized conditions, the linear range of concentrations of CO was 0-2.7×10~(-6), r=0.999,p<0.0001. The relative standard deviation of the analysis method was <4.4%, with a detection limit of 0.02 nmol/L. The average recovery of CO was 90.5%. The concentrations of CO in surface waters of the North Yellow Sea were measured using this method and ranged from 0.20 nmol/L to 3.13 nmol/L, indicating that this method can be successfully applied to the detection of the in situ CO concentrations in seawater.
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Objective: To establish a HS CGC method for the analysis of residual petroleum ether (60～90?C) in Kanglaite Capsules.Methods: Headspace sampling, a fused silica analytical column with cross linked 95% dimethyl and 5% diphenyl siloxanes station phase (30m?320?m?0.25?m), column temperature at 40?C, a linear velocity of about 19 cm per second, FID detector.Results: The average recovery is 97.2% (RSD=2.87%, n=5). The minimal detection limit is 2.65?10 -8 g?mL -1 (signal/noise=1.3).Conclusion: The method is simple and accurate, and can be used as a control method for the residual organic solvent in the capsules.