[Several methods for determining total titers of free alpha-amino acids in body fluids].

Comparisons were made among different variants of ninhydrin reaction to determine overall titres of free alpha amino acids in body fluids. Included were para-benzoquinone, 2,4,6-trinitrobenzene sulphonic acid, and 2,4-dinitro-1-fluorobenzene (DNFB). The best reproducibility of results was recorded from DNFB which can be used, as well, for analysis of milk or rumen juice.