A rapid analytical method was developed to quantify
dibasic amino acids (
ornithine,
lysine and
arginine) after two-step derivatization procedure with good sensitivity and specificity on human plasma. If early diagnosis has not been made, patients with inborn metabolic disorders such as
HHH syndrome, Hyperornithinemia and dibasic aminoaciduria rapidly progress to
sudden death, physical defect or
mental retardation resulting in storage of the toxic material into the brain. Therefore, it is necessary to develop the analytical method for rapid screening and/or correct confirmation diagnosis. The formation of trimethylsilyl derivative of the carboxylic (
COO-) functional group was performed by adding
MSTFA. Five μL of
methyl orange was added to the residue until the color changed into yellow. Consecutively, the trifluoroacyl derivative of the amino (-NH2) functional group was produced by adding MBTFA. Specific
ions was chosen for quantification with following
ions; m/z 166 and m/z 212 for
ornithine, m/z 180 and m/z 395 for
lysine, and m/z 292 and, m/z 519 for
arginine. A calibration curve showed a linear relationship for the
dibasic amino acids spiked to pooled normal plasma showing R(2) of 0.9955-0.9979 in the range of 0.1-600 ng investigated. The utility of the method for screening and diagnosis was demonstrated by recovery 80-125 % and reproducibility with RSD (9-17 %) at low, medium and high concentration fortified to pooled plasma. Collectively, the present study suggest that this method could be useful for diagnosis, screening, therapeutic monitoring of metabolic disorders on dietary
therapy with excellent sensitivity and rapidity.