Determination of magnesium by the Titan yellow and ammonium phosphate methods.

The ammonium phosphate and Titan yellow methods for determining magnesium have been investigated, and improvements to both techniques are presented. The Titan yellow method is shown to be subject to interference which makes it unsuitable for the analysis of blood cells, food, and faecal materials, and may also affect its reliability with pathological samples of serum and urine. The relative insusceptibility to interference of the ammonium phosphate method makes it more reliable than the Titan yellow method with pathological specimens, and slight modifications permit the use of the same basic procedure with blood, urine, and solutions of food or faecal ash.