OBJECTIVE: To establish a method for detection of 2-methylpropanal,2-methyl butanal and 3-methyl butanal in workplace air by portable gas chromatography-mass spectrometry( GC-MS). METHODS: The workplace air was collected by portable GC-MS sampling probe. After enrichment by Tri-bed tube,the thermal desorption sample was analyzed by retention time and characteristic ion characterization. The characteristic ion peak area was quantified. RESULTS: The linear ranges of 2-methylpropanal,2-methyl butanal and 3-methyl butanal were 0. 079-15. 880,0. 080-16. 080 and 0. 161-32. 120 mg/m~3,respectively. All the correlation coefficients were greater than 0. 999. The detection limits were 0. 012,0. 007 and0. 013 mg/m~3,and the quantitation limits were 0. 041,0. 023 and 0. 044 mg/m~3,respectively. The recovery rates of2-methylpropanal,2-methyl butanal and 3-methyl butanal were 92. 2%-104. 4%. The within-run relative standard deviation( RSD) was 5. 8%-9. 1%. The between-run RSD of different batches samples was 9. 3%-19. 6%. CONCLUSION: This method has high accuracy and is precise,which is suitable for rapid qualitative and quantitative detection of2-methylpropanal,2-methyl butanal and 3-methyl butanal in workplace air.

OBJECTIVE: To establish a method for simultaneous detection of 16 kinds of gas and particle-phase polycyclic aromatic hydrocarbons(PAHs) in workplace air by high performance liquid chromatography with ultraviolet and fluorescence detector(HPLC-UV-FLD).METHODS: PAHs in workplace air were collected by polytetrafluoroethlene filter with XAD-2 tube. The samples were added with 5 mL of acetonitrile. The samples were extracted by ultrasound and eluted with acetonitrile-water gradient. Ultraviolet with tandem fluorescence detector was used for determination.RESULTS: Eleven kinds of PAHs showed a good linear range of 1.0-400.0 μg/L. Five kinds of PAHs showed a good linear range of 10.0-2 000.0 μg/L and the linear correlation coefficient was greater than 0.999 0. The minimum detection concentration was 0.000 01-0.000 67 mg/m~3 (75 L air sample). The average elution efficiency of filter on granular PAHs except for naphthalene and acenaphthene ranged from 71.0% to 99.0%. The average desorption efficiencies of adsorbent tube was 43.0%-90.0%. The within-run relative standard deviations(RSD) was 0.3%-8.3%, and the between-run RSD was 0.0%-9.2%.CONCLUSION: This method is simple, sensitive, has good linear range and precise. It is suitable for simultaneous detection of PAHs in workplace air.