[Determination of trace silver by flame atomic absorption spectrometry using chitosan enriching method].

A method for the determination of trace silver by flame atomic absorption spectrometry using chitosan enriching method has been investigated. The conditions that influence the adsorption of silver by chitosan were studied. The optimal flow rate of the sample solution was 1 mL x min(-1), and the optimal sorption (96.7%) was possible by using the systems with pH 6.0 for silver. The amount of saturated adsorption of silver in the chitosan was 97.8 mg x g(-1). Silver was eluted from the chitosan by 1 mol x L(-1) H2SO4. 100 mg x mL(-1) of Al3+, Cr3+ and 80 mg x mL(-1) of Ni2+, Cu2+, Pb2+ and Zn2+ did not disturb the determination of silver. K+, Na+, Ca2+, Mg2+ and Mn2+ did not disturb the determination of silver because they were not adsorbed by chitosan. The method has been applied to the determination of silver (1.83 microg x mL(-1)) in waste water sample with a recovery of 94.3%.