Materials and Methods Instrumentation Sampling Handling and Presentation

A procedure is presented for the automated determination of serum calcium by atomic absorption spectrophotometry. The serum sample, diluted with acidified lanthanum trichioride, is dia’yzed against 0.1 N hydrochloric acid and a portion of the recipient solution is pumped into the atomizer-burner of the spectrophotometer. Data are presented on the precisionand reproducibility of the flow system. Addition of calcium to serum shows a mean recovery of 99%. A comparison of the results of analyses on random specimens by permanganate titration and the automated pro-cedure shows good agreement. IN THE CONTINUING program of our laboratory to develop automated analytic procedures for both biochemical and clinical research, it was of interest to determine the feasibility of automated atomic absorption spectroscopy for the analysis of serum calcium. The general procedure presented in this paper applied the manual methods developed earlier by Willis (1) and, more recently, by Zettner and Seligson (2)