Spectrographic Studies of Human Blood

Many of the vitamins in the blood have been investigated by chemical and biological methods including vitamin A by photo-electric colorimetric analysis (1), vitamin B1 by a fermentation method (2), nicotinic acid by a microbiological assay with Shigella paradysenteriae ( 3), pantothenic acid by measuring the growth of such bacteria as Proteus morganii (4), and Lactobacillus casei E (5), vitamin C by 2, 6-dichlorophenolindophenol (6), (7), (8), vitamin D by a colorimetric method (9), and vitamin K by measuring the clotting power of the blood (10). According to the above methods, these vitamins are present in blood and some of them cannot be found by any other means. Furthermore many of these reactions are not specific. Moreover, the constitution of blood is so complicated that it is almost impossible to apply any chemical analysis without altering its nature. Some of its constituents are present in such minute amounts that they are beyond chemical detection. Spectrographic analysis has the advantage of permitting the detection of small amounts of material and avoiding the previous chemical separation of compounds which do not absorb. Hence it was thought worthwhile to apply spectroscopy to the analytical study of blood