Comparison of Protein Precipitants for the Determination of Free Amino Acids in Plasma

作者：Ikuo Ohara, Shujiro Ariyoshi · 发表于：Agricultural and Biological Chemistry · 年份：1979 · DOI：10.1080/00021369.1979.10863637 · 被引用次数：30 · 研究领域：Amino Acid Enzymes and Metabolism、Biopolymer Synthesis and Applications、Metabolism and Genetic Disorders

The present study was undertaken to select the most preferred deproteinizing agent for microbiological or chromatographic determination of free amino acids in plasma. The highest quantities of amino acids were obtained from samples treated with picric acid, ethanol or sulfosalicylic acid. It was also found from examining the recoveries of 14C-labeled amino acids added to plasma following treatment with picric acid, ethanol and sulfosalicylic acid that one kind of deproteinizing agent is not equally effective with all amino acids. Picric acid treatment gave the most reliable results for determination of amino acids except the basic amino acids, alanine and tryptophan. Sulfosalicylic acid was the most recommended deproteinizing agent for basic amino acids and ethanol was good for the assay of alanine and tryptophan. The response of d-amino acids to the deproteinizing agents tested was not always similar to that of their l-isomers.