摘要：In order to develop a system for the separation of amino acids-conjugated metabolites of toxic compounds or drugs in biological samples, the ability of activated carbon to separate amino acids was investigated thin-layer chromatographically. Several kinds of thin-layer chromatoplates of activated carbon were prepared by using calcium sulfate (CaSO4·1/2H2O), cellulose powder or Silica Gel G as a binder. Standard amino acids were chromatographed with water and aqueous acetic acid as solvents. With water, the results were as follow : Rf value zero for Trp, Tyr and Phe : 0-0.3 for Leu, Ile, Met, His, Arg and Cys ; 0.3-0.7 for Val, Pro, Glu, Hyp, Asp, Thr and Lys ; 0.7-1.0 for Ser, Ala and Gly. The thin-layer chromatograms on activated carbon plates could be used to locate the migration positions of amino acids chromatographed on a long chromatocolumn of activated carbon. Preparative thin-layer chromatography on activated carbon was also useful for the purification of metabolites. This preparative method was utilized in a multistage chromatocolumn system in order to treat a large quantity of sample solution or sample extracts. This column system was prepared by connecting several short chromatocolumns of activated carbon. This system could be utilized for the detection of 2-(2-amino-2-carboxy-ethylthio)-3-methylbutyrylurea in the urine of a person given α-bromoisovalerylurea.
