Potassium Iodide Test for Lead on a tapelift
This is a positive test for lead on an
environmental tapelift collected in a lead/acid battery recycling
plant. Half of the tapelift was exposed to a drop of potassium iodide which was then
blotted off. The tape was dried and then processed as normal.
The particles that turned bright yellow contain lead.
Reflected Darkfield Illumination
Definition/Function:
Lead containing particles on an environmental tapelift can be detected by adding a small
droplet of 10% nitric acid which is then blotted off,
followed by a 10% droplet of potassium iodide and blotting that off. The result is a
bright flash of yellow on the particles that contain lead.
The tapelift is dried, applied to a clean microscope slide and processed as normal. The
lead containing particles can then be identified in the
environment with respect to the other particles in the environment. In this case the
lead salts were sparingly soluble in water so the nitric
acid pretreatment was not necessary.
Significance in the Environment:
Characteristic Features:
Associated Particles:
References:
Chamot, Emile Monnin and Clyde Walter Mason, HANDBOOK OF CHEMICAL MICROSCOPY, Volume II,
pp. 203-4, 1940.
