[Modified Method for Measuring Levels of Organomercury Compounds in Household Products]

In Japan, the use of organomercury compounds is regulated in textile products (diapers, diaper covers, bibs, underwear, sanitary pads, sanitary panties, gloves, hosiery), adhesive, paint, wax, and shoe polish buffers. This is stated in Act No. 112 of 1973, 'Act on Control of Household Products Containing Harmful Substances'. In this study, we modified the currently used official method. The modified method uses cyclohexane/ethyl acetate (3 : 1) as the extraction solvent instead of carbon tetrachloride. The phenyl mercuric acetate as the organomercury compounds was quantified by a direct thermal decomposition mercury analyzer accurately, precisely, and safely. The calibration curves for determining the level of phenyl mercuric acetate were shown to be linear in the range of 0.12-6.0 ng mercury (Hg). The quantitation limit (Hg: 4.7 ng/g) was adequately low relative to the regulation value (Hg: 1 µg/g). The modified method exhibited a recovery rate of phenyl mercuric acetate in various household products of 38-87% with relative standard deviations of 1.5-19.5% when the standard solution (60 ng Hg) was added to the samples (1.0 g). In addition, we found that the use of suction filtration during the extraction from textile products such as thick socks provided high recovery. Thus, the modified method would be applicable for measuring levels of the organomercury compounds in various controlled household products.