On the Determinations of Magnesium Content in the Rabbit Plasma by Atomic Absorption Spectroscopy

Magnesium in the rabbit plasma was determined in a simple dilution with six kinds of the diluents, such as 0.1N hydrochloric acid, 0.25% strontium chloride solution, 0.5% lanthanum chloride solution, 1% EDTA solution, the solution similar to the serum, and water by atomic absorption spectrophotometry, and then these results were compared with those obtained from the same specimens analysed by the colorimetric assay for magnesium (Magnesium kit-N method). In addition, the accuracy of the technique and the interference by some cations and anions have also been investigated. The results were as follows. 1. The calibration curves of magnesium for six kinds of the diluents and those in the additon of a definite amount of magnesium to plasma together gave the straight line according to the law of Lambert-Beer. 2, The magnesium values in the rabbit plasma measured by six kinds of the diluents nearly agreed. On the contrary, the correlation coefficient between each of these values and that by colorimetric method was appreciably different from each other and it was the highest in a simple dillution with 0.1N hydrochloric acid, followed by 1% EDTA solution similar to the serum 0.25% strontium chloride solution, 0,5% lanthanum chloride solution, and water in order of lowering values. 3. Of the interferential materials tested, Ni2+ strongly interfered magnesium absorption, whereas the interference by other ions was very slight