Kikuo Tamase

High-performance liquid chromatographic analysis of ammonium in human urine

A method for the quantitative determination of ammonium in human urine by high-performance liquid chromatography (HPLC) is described. After making fluorescent substances with fluorescamine, they were separated and quantified by their fluorometric intensity. The intensity (as measured by peak height) was linear between 0.5 and 5.0 micrograms, and coefficients of variation for elution time and peak height on replicate analysis of the standard were 0.15 and 4.2%, respectively. Recoveries of added ammonium were 96.5 and 97.3%, respectively, on 2.0 and 3.0 micrograms by this method. Detection limit of this method was 0.2 microgram. There was good agreement between the proposed HPLC method (X) and ion chromatographic method (Y), giving the relationships as Y = 0.956X + 0.012, r = 0.991.

Composition of fatty acids and their characteristics in oil of instant Chinese noodles.

Twenty-two kinds of oil samples extracted from instant Chinese noodles were analyzed on their composition of fatty acid methyl esters by GC. Four main fatty acids in the oil were 18 : 1, 16 : 0, 18 : 2, and 18 : 0, and another trace ones detected were 14 : 0, 16 : 1, 17 : 0, 17 : 1, 18 : 3+20 : 0, 20 : 1, and 20 : 2. Constraction values of these four main fatty acids were used to evaluate and to calculate the difference among the six producing companies by a personal computer with the analytical method of principal component analysis. Samples were divided into three groups. The constraction values of company B was similar to that of the palm oil and another ones of companies A and E were also similar to that of the mixed oil with the ratio of 25 to 75 on the palm oil and lard.