Bioassay of Mercury Vapor Arising from a Phenyl Mercury Compound.

Abstract

Mercury vapor has been detected quantitatively by a bioassay in connection with a study on the liberation of mercury vapor from paint films containing phenyl mercury compounds. This assay depends upon the ability of small quantities of mercury vapor to prevent foliar abscission of bean plants in vitro. Although chemical methods exist for detecting mercury vapor, these methods were found unsuitable in the present problem. Thus palladium chloride paper darkened when confined with paint films containing no mercury or with portions of living plants. Selenium sulfide paper was likewise not sufficiently selective and was less sensitive than palladium chloride paper to mercury vapor. Detection of mercury vapor through its absorption of ultraviolet radiation of wavelength 2537 A is the basis of a vapor detector manufactured by the General Electric Co. Although this instrument is sensitive, it is not generally available in laboratories. The bean assay is presented here because it requires no special equipment, is simple, rapid and inexpensive, is quantitative in the range from 0.06 to 0.9 mg mercury per m/sup 3/ of air, and is selective for mercury vapor in the presence of materials which interfere with other standard spot tests for mercury referred to above.