This report concerns the simultaneous analysis of the anomalous metabolic amino acids of three illnesses targeted by the Ministry for Health and Welfare (homocystinuria, maple syrup urine disease, phenylketonuria): methionine (Met), leucine (Leu), phenylalanine (Phe), valine (Val), tyrosine (Tyr), isoleucine (Ile).

The time for analysis of a single specimen is 15 minutes. Detection employs OPA post column derivatization. The use of a micro-plate enables easy simultaneous pre-processing of multiple samples.