关键词: 预富集, 活性炭, 石墨炉原子吸收法, 铅, 镉

Abstract:

A method was developed for the determination of lead and cadmium in beverage by graphite furnace atomic absorption spectrometry(GFAAS) after pre-concentration. The trace lead and cadmium ions was chelated with ammonium pyrrolidine dithio carbamate (APDC), and fixed on active carbon at pH 4.0－7.0. Then the active carbon was collected on through vacuum filtration, washed with 1ml of diammoniumhy drogenosphate solution (10 g/L) containing 0.2% nitric acid, and the suspension was directly used for the determination by GFAAS. Concentration of lead and cadmium in beverage samples was 2.50×10-12 g, 6.94×10-13 g respectively, with the relative standard deviation(RSD) from 3.04% to 6.21% and spike recoveries from 97.9% to 107.0%. This method could be used to determinate trace heavy metal in beverage.

Key words: preconcentration, active carbon, graphite furnace atomic absorption spectrometry, lead, cadmium