THE RAPID DETERMINATION OF LEAD ON FILTER PAPER

Abstract

In alkali solution, diphenylcarbazide reacts with lead and produces a water soluble complex of deep red. The author intended to determine lead on the filter paper using this reaction. The fixed volume of lead solution was spotted on the filter paper and was developed with diphenylcarbazide. Then the area of developed spot increased logalithmically with the increasing concentration of lead solution. By this method, 150 γ of lead can be determined easily and quickly. When the lead solution was spotted on the narrow filter paper (2 mm or 4 mm in width), lead could be determined from the length of colored part. Limit of identification by this method is about 0.01γ lead, and limit of determination is about 0.1 γ lead.