Determination of calcium intake of help of atomic absorption spectrophotometry.

In a dietary survey, large numbers of a wide variety of food samples have to be analyzed. The atomic absorption spectroscopy (AAS), with its simplicity, accuracy and rapidity, suggests itself for determination of many elements in such a case. In this investigation, calcium determination by AAS is reviewed. Analytical parameters, interferences and their control are studied. Food samples are dry ashed and treated so as to eliminate silicates. Most serious interference comes from phosphates and is successfully controlled by addition of lanthanum. Calcium is determined in the range 2-10 ppm with a sensitivity of 0.1 ppm. Single food samples and samples representing food mixtures are analyzed, and calcium intake of different population groups is computed. In most cases, results compare favourably well with those obtained from food composition tables. Calcium intake in the Netherlands both of the average per caput and of chosen population groups is found to cover the recommendations except for infants. Differences do exist between intakes of different groups and in different seasons.