ABSTRACT
OBJECTIVE: To establish a method for simultaneous determination of chlorobenzene, p-dichlorobenzene and o-dichlorobenzene in workplace air by portable gas chromatography-mass spectrometry(GC-MS). METHODS: The portable GC-MS heat tracing sampling probe was used for sampling. Samples were separated with LTM DB-5 MS rapid chromatographic column. The qualitative analysis was based on retention times and characteristic ions, and the quantification was based on standard curves. RESULTS: The linear correlation coefficient of this method was higher than 0.999 6. The minimum detectable concentrations were 0.03, 0.03 and 0.06 mg/m~3, and the minimum quantification concentrations were 0.10, 0.10 and 0.20 mg/m~3. The recovery rates were 84.68%-92.61%, 86.27%-93.92% and 82.31%-92.36% respectively for three chlorobenzenes compounds. The within-run relative standard deviations(RSD) were 8.51%-9.34%, 7.93%-9.19%, 5.47%-7.48% respectively for three chlorobenzenes compounds, the between-run RSD were 7.29%-9.73%, 8.08%-10.04% and 5.19%-5.98% respectively for three chlorobenzenes compounds. CONCLUSION: The portable GC-MS could be used for qualitative and quantitative detection of three chlorobenzenes compounds in workplace air.
ABSTRACT
OBJECTIVE: To establish a method for determination of N-methyl-2-pyrrolidone(NMP) in workplace air by solvent desorption-gas chromatography. METHODS: NMP in the workplace air was collected with activated carbon tube and desorbed with methanol ∶dichloromethane(5 ∶95, V/V). After desorption, it was separated by capillary column separation, and detected by flame ionization detector. RESULTS: The good linear concentration of NMP was 0.51-4 108.00 mg/L. The correlation coefficient was 0.999 9. The detection limit was 0.08 mg/L(calculated by 3 times of standard deviation). The average desorption efficiency was 101.68%-103.44%. The within-run and between-run relative standard deviations were 1.94%-3.97% and 0.97%-2.26%, respectively. The sample could be stored at room temperature for at least 14 days. CONCLUSION: The developed method is suitable for the determination of NMP in workplace air.