摘要：A brief A. C. polarographic method has been studied for the determination of trace amounts of lead in several plants. The ash (below 300mg) by dry digesting was treated in excess hydrochloric acid, and evaporated to dryness. The residue was taken up in 5 ml of mixture of 0.4 N hydrochloric acid and 0.4 M tartaric acid, and stirred for ten minutes. The solution was transferred to a 10ml volumetric flask, made up to the mark with the mixture, and the polarogram of lead was recorded at -0.3∼-0.6V. It was found that tartaric acid had a nature of suppressing of a large peak due to the charging current of hydrochloric acid, and a mixture of supporting electrolyte had little influence of dissolved oxygen and soluble coexisting ions on the determination of lead.
