Determination of Calcium and Magnesium by Atomic Absorption Spectrophotometry and Its Application to the Water Analyses

Abstract

Atomic absorption spectrophotometric investigations of calcium and magnesium, with airacetylene flame, were carried out by the use of Shimadzu Multichannel Atomic AbsorptionFlame Spectrometer, Model MAF-1, and fundamental conditions were examined with an aim of its application to the analysis of calcium and magnesium in water.
The condition recommended for calcium and magnesium determination were as follows, wavelength; 4227 A and 2852 A, hollow cathode lamp current; 11 mA and 10 mA, slit width; 0.05 mm and 0.05 mm, acetylene pressure; 0.3 kg/cm² and 0.3 kg/cm², air pressure; 1.4 kg/cm² and 1.4 kg/cm², respectively.
Coexisting elements except large amounts of silicon, aluminium, titanium and vanadium did not interfere the determination. Chemical interference could be minimized on calcium by the addition of 5000 ppm of lanthanum to the unknown and standard samples, same interference to magnesium could be minimized by the addition of 50 ppm of calcium.
The relative determinations were less than 4.7%, and the results were satisfactorily coincident with those obtained by other methods.