Determination of vitamin D2 in gelatin-protected vitamin A acetate/vitamin D2 beadlets by high pressure liquid chromatography

1974 ◽  
Vol 46 (11) ◽  
pp. 1602-1604 ◽  
Author(s):  
David F. Tomkins ◽  
Ronald J. Tscherne
1982 ◽  
Vol 65 (3) ◽  
pp. 619-623
Author(s):  
Maria Ines ◽  
R M Santoro ◽  
João F Magalhães ◽  
Erika R M Hackmann

Abstract Vitamins A and D were determined simultaneously in oily solutions, ointments, and elixirs, but only vitamin A could be determined in capsules. Samples were saponified with KOH in isopropanol-water, using hydroquinone as antioxidant, and extracted with ether-petroleum ether (1 + 1). After evaporation of solvent, residues were dissolved in isopropanol. Vitamins in these solutions were determined by reverse phase high pressure liquid chromatography, using methanol-water as mobile phase and detection at 254 nm. The reproducibility, using external standards, was 1.6-2.5% and 1.2-3.8% for vitamins A and D, respectively.


1982 ◽  
Vol 65 (3) ◽  
pp. 651-654
Author(s):  
Beatriz Ferreira Engelke ◽  
Phillip G Vincent

Abstract Different particle sizes of blade- and ball-milled poppy straw were separated and analyzed for morphine by high pressure liquid chromatography. Morphine content varied up to 70% among the different size particles. This may account for discrepancies observed in percentages of morphine found among random aliquots. Homogenizing a carefully quartered sample of blade-milled straw by further pulverization in a percussion ball mill 2 min and taking a quartered aliquot for morphine analysis improved the reproducibility of results.


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