Determination of Trace Lead and Cadmium in Water by Separating and Enriching With Sulphydryl Cotton and Flame Atomic Absorption Spectrophotometry

Objective To develop a method to determine trace Pb and Cd in mineral water, tap water and sea water. Methods Pb and Cd in the samples were enriched in the sulphydryl cotton column under the conditions that the pH of the samples was adjusted to 7 and collected by washing the column with 4 ml of 0.2 mol/L HCl solution. The concentration of Pb and Cd was determined by flame atomic absorption spectrophotometry. Results Pb and Cd were not detected in four kinds of mineral water samples, but in tap water and sea water, Pb was 1.56 μg/L and 0.43 μg/L, Cd was 0.62 μg/L and 0.07 μg/L respectively. The rates of recovery were 96.6%-104.0% and RSD was 5%. Conclusion Trace Pb and Cd in water samples could be detected out by separating and enriching with sulfhydryl cotton and flame atomic absorption spectrophotometry. This method is quick and precise.