Abstract
A new micro-injection system for flame atomic absorption spectrometry has been devised. In this system, a small amount of sample, 20 to 100μl, is injected in the stream of a carrier solution through a sample inlet and thenfed into a nebulizer. Use of the carrier solution is found to be effective to minimize a sample volume and to reduce physical and chemical interferences. The carrier solution of water reduces the physical interference caused by the increased viscosity of sample solution which contained 5% albumin, and the carrier solution of 2000 ppm lanthanum suppresses the chemical interference caused by aluminum and phosphoric acid in the determination of magnesium and calcium. This method has been successfully applied to the determination of magnesium, calcium, copper and zinc in serum. The analytical results agreed well with those obtained by conventional flame atomic absorption, the relative standard deviation (RSD) being less than 5.1%
