1981 Volume 35 Issue 1 Pages 28-32
In order to determine automatically the magnesium ion of salt manufacturing samples, the authors made an investigation on Technicon's auto-analyzer by the colorimetric method with xylidylblue-II reagent, and then examined the effects of ethanol concentration of sample solution and of coexisting ions. The following were the results obtained from this study: 1) The reaction between magnesium ion and xylidylblue-II reagent is influenced by the alcoholic concentration. Therefore, it is necessary to control the alcoholic concentration to 54%(the final content). 2) Interference by the coexisting ions such as Na+ and Ca2+can be eliminated by the addition of G-EDTA reagent.
In this method, a linear relationship is obtained between the absorbance and the concentration of magnesium ion in the range of 0-20mg/l.
This method has the same accuracy as the conventional EDTA method, and can analyze continuously 15-20 samples per hour.