Determination of Milk Minerals by Flame Photometry

Abstract

A Beckman spectrophotometer with flame attachment was used to determine Ca, K and Na in milk. Magnesium could not be detd. because of its unfavorably low concn. The technic proposed consisted of dissolving the ash from a milk sample to approx. concns. of 12 ppm. Ca, 4 ppm. Na, and 12 ppm. K, and determining the relative intensity of the desired ion. Immediately following this reading the relative intensities of 2 standards, one of slightly lower concn. and the other of slightly higher concn. than the unknown, were taken and the unknown concn. detd. by interpolation. The effects of extraneous ions upon the relative intensity of the desired element were minimized by incorporating the influencing ions in the standards in approx. the same concns. as they appeared in the unknown and, in special instances, by the application of a predetermined correction. Results compared favorably with chemical results.