One-Drop Flame Atomic Absorptiometric Determination of Copper, Cobalt and Nickel in Pepperbush Using Direct Nebulization of Chloroform Extract

Abstract

After the microwave acid digestion of a solid sample of 100 mg in a sealed double PTFE vessel with a polypropylene jacket and the extraction removal of iron with Hinokitiol into benzene, copper, cobalt and nickel were extracted with ammonium pyrrolidinedithiocarbamate into chloroform. Direct injection of the chloroform extract into a flame gave an characteristic signal profile for Cu, Co and Ni. Injection volumes of 35–45 ul of the chloroform extract gave the highest, most constant and most reproducible signals. When we nebulized 40 μl of the chloroform extract, three metals were well determined by one-drop flame atomic absorption spectrometry with deuterium background correction. The method was successfully applied to the determination of three elements in a certified reference material (NIES-CRM No. 1, Pepperbush) from the National Institute for Environmental Studies; the result agreed well with the certified values.