Interference correction for determination of cadmium,chromium,manganese,nickel and lead in workplace air by ICP-AES / 中国职业医学

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.