A semi-quantitative test for mercury in air.

Abstract

A simple method for semi-quantitative detection of mercury vapour in air is described. The method is based on the well-known reaction between the yellowish-brown PdCl2 and mercury vapour resulting in the formation of gray colloidal palladium. Discs of Alter paper are impregnated with a 1% PdCl2 solution, dried, and suspended in the air whose mean mercury vapour concentration during a given period of time is to be analyzed. For the low mercury vapour concentrations to be expected in a dental office or laboratory, an exposure time of the test paper of 1—4 weeks is probably indicated. The mean mercury vapour concentration during the exposure time can be estimated colorimetrically by means of a gray-color scale. The sensitivity of the method is better than 0.01 mg Hg/m2 air at an exposure time of 4 weeks. The accepted maximum concentration of mercury vapour in air for prolonged exposure of human beings (the so-called threshold limit value) is different in different countries; for Denmark it is 0.05 mg/m3.Carb...