Coprecipitation of Cu(II), Ni(II), Fe(III), Cd(II), Pb(II), and Co(II) in wastewater, sediment, and metallic zinc samples with HMDTC-HMA for flame atomic absorption spectrometric determination

A preconcentration method was presented for determination of Cu(II), Ni(II), Fe(III), Cd(II), Pb(II), and Co(II) ions in wastewater, certified stream sediment and certified metallic zinc samples by flame atomic absorption spectrometry. The procedure is based on collection of analytes on a cellulose nitrate membrane filter following their coprecipitation with hexamethylene-dithiocarbamic acid hexamethyleneammonium salt (HMDTC-HMA). Several parameters including pH of sample solution, amount of carrier, and volume of sample solution, governing the efficiency and throughput of the procedure were evaluated. The influences of matrix ions of the real samples on recoveries of analytes were also investigated. The detection limits based on the 3sigma criterion was in the range of 5.9 mug/L for Cd-6 1.0 mug/L for Pb. The recoveries were > 95%. The relative standard deviation of the determination was less than 10%.