The determination of vitamin A in cod-liver oils (a) biologically, (b) chemically, (c) physically, with a statistical examination of the results

Publisher Website
Google Scholar
Abstract
The biological measure was resumption of growth in rats, the blue value with SbCl3 was measured by the Lovibond tintometer and the intensity of UV absorption was measured spectrophotometrically. Statistical examination showed the discrepancies between the physical and biological measurements to be much larger than the known sampling error of the biological test and that the Lovibond blue values could be used only as a very crude indication of vitamin A potency in oils.