Automated fluorometric determination of vitamin A in milk
Thompson, J.N.; Madère, R.
Journal - Association of Official Analytical Chemists 61(6): 1370-1373
1978
ISSN/ISBN: 0004-5756 PMID: 569656 Document Number: 128167
A previously published fluorometric method for vitamin A in milk, involving saponification in centrifuge tubes and extraction with hexane, was automated using conventional automated equipment including a filter fluorometer. The extraction and separation steps were affected by the presence of fat, so standards were prepared in milk. The peaks obtained with samples were 95% of steady state values. The coefficients of variation for 10 replicate analyses were 1.9% for unfortified milk and 1.3% for fortified milk. In tests on 19 different milk samples, the results of the automated and manual fluorometric methods differed by less than 10%; a colorimetric method using SbCl3 gave more erratic results and was more lengthy and laborious.