ABSTRACT
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.
ABSTRACT
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.
ABSTRACT
OBJECTIVE: To explore the interference correction reduction method for the determination of cadmium(Cd), chromium(Cr), manganese(Mn), nickel(Ni) and lead(Pb) concentration in workplace air by inductively coupled plasma-atomic emission spectrometry(ICP-AES). METHODS: The interference sources in the determination of metals in workplace air with ICP-AES was analyzed. The results before and after the background correction or the internal standard calibration were compared. Linear regression is performed on the interference element mass concentration by interference error to obtain a table of interference factors. The measurement results of actual samples were corrected using background subtraction, internal standard correction, and interference factor method. RESULTS: The relative deviation of results and theoretical values without background subtraction were 219.5% and 131.5% for Cd and Pb, respectively. The relative deviation between the measured values and theoretical values was less than 10.0% after background subtraction. When the total metal ion concentration was >800.00 mg/L, the relative deviation between measured result and the theoretical values was-21.0%--11.0% without internal standard correction, and the absolute value of them were less than 10.0% after internal standard correction. The interference correction method was used to correct the concentration of Cd, Cr, Mn, Ni, Pb in welding smoke. The mass concentrations of Cd before and after interference correction were 3.90-32.50 and 1.20-7.10 μg/L, respectively. The mass concentrations of nickel before and after interference correction were 111.00-1 220.00 and 99.00-1 120.00 μg/L, respectively. The mass concentration of Cr,Mn and Pb remained unchanged before and after the interference correction. CONCLUSION: The background correction, internal standard correction and interference factor table can eliminate the interference for determination of metals in workplace air by ICP-AES and ensure the accuracy of results.