Mercury in biological materials.
نویسندگان
چکیده
The present communication is concerned with the determination of mercury in biological materials and its normal excretion in humans. As a preliminary step in the determination of mercury in biological materials, destruction of the organic matter is essential. Mercury has a high degree of volatility and hence precautions are necessary to prevent losses during this process. There have been many communications on this subject (cf. Sandell, 1950), but the simpler procedures are mostly applicable to urine only. Abbott and Johnson (1957) have described a relatively simple procedure for the determination of mercury in apples. The material is heated with a mixture of sulphuric and nitric acids in the presence of selenium in a special reflux apparatus. Oxidation is completed by the addition of hydrogen peroxide. This procedure has been found to be applicable not only to urine but to faeces and tissues. The hydrogen peroxide has been replaced by potassium permanganate, since a lower blank value can thus be obtained. The most convenient method for the colorimetric determination of mercury is with dithizone using a reversion technique (cf. Irving, Risdon, and Andrew, 1949). Of the reversion techniques described, that using sodium thiosulphate in an acid medium (Abbott and Johnson, 1957) has been used. The use of a reversion technique involves two photometric measurements: (a) a solution containing unchanged dithizone and the metal dithizonate; and (b) the previous solution after reversion, now containing the original unchanged dithizone and dithizone derived from the metal dithizonate. The difference between these two measurements is representative of the quantity of metal dithizonate present in (a). Assessment may be made by taking readings at the wavelength of maximum absorption of dithizone, i.e., 620 mpt, or of the metal dithizonate, i.e., 430 m,u for mercury dithizonate. The differences are much greater at 620 m/u than at 430 m,u. At 620 my the differences (b-a) are positive, while at 430 m,u they are negative. It was therefore decided that
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عنوان ژورنال:
- Journal of clinical pathology
دوره 12 3 شماره
صفحات -
تاریخ انتشار 1959