Determination of cadmium and zinc in fertilizer samples by FAAS after solid-phase extraction with freshly precipitated manganese-diethyldithiocarbamate.

Using freshly precipitated manganese-diethyldithiocarbamate (Mn(DDTC)(2)) as a new reagent, a solid phase extraction method (SPE) has been developed for the extraction of Cd(II) and Zn(II) in aqueous fertilizer samples. A sample solution of 300 mL was taken and 0.10 g of freshly precipitated Mn(DDTC)(2) was added. After adding a phosphate buffer solution, the mixture was stirred at 10 min, filtered with a glass filter and washed with deionized water. The solid product containing Mn(DDTC)(2)-Cd(DDTC)(2)-Zn(DDTC)(2) complexes was dissolved in concentrated nitric acid and its volume was made complete up to 10 mL with deionized water. The metal contents of the solution were measured by an atomic-absorption spectrometer.