Determination of Zinc in Aerosol Samples by Discrete Nebulization Flame Atomic Absorption Spectrometry


Abstract: A well-known analytical method, ``discrete nebulization'', which is suitable for samples having a limited amount like body fluids, high solid content or salt solutions, and less volatile metals, has been further developed for zinc determination in aerosol samples. The effects of injection volume and nebulizer aspiration rate on absorbance and precision were studied. A calibration graph was obtained linearly up to 1.75 mg/L Zn with a 0.9988 correlation coefficient and 3.09\% RSD using 50 \mu L injection volume, values comparable to conventional continuous nebulization. The detection limit (3S) achieved by the method was calculated to be 1.09 ng or 0.020 mg/L for 50 \mu L injection volume. A hydrophobic PTFE micro sampling cup was used. Aerosol samples were collected between January 1996 and December 1998 in Mersin, Turkey, using polycarbonate filters. Collected samples were digested in the presence of HNO_{3} and HF. Digested samples were analyzed for zinc using discrete nebulization flame atomic absorption spectrometry (FAAS). The validity of the proposed method was established by evaluating the accuracy of analyses of BCSS-1 (Marine Sediment Reference Materials for Trace Metals and Other Constituents) CANADA. For the given true value of 119.0 ± 12 mg/Kg zinc, a value of 118.98 ± 0.26 mg/Kg zinc was found with a precision of 0.22\% RSD. As a further check on accuracy, recoveries from aerosol samples were examined and found to be 94-102\% , again testifying to the reliability of the proposed method.

Keywords: Discrete nebulization, FAAS, zsinc, aerosol samples, flame micro sampling.

Full Text: PDF