PMID- 28565794 OWN - NLM STAT- PubMed-not-MEDLINE LR - 20200929 IS - 1792-0981 (Print) IS - 1792-1015 (Electronic) IS - 1792-0981 (Linking) VI - 13 IP - 5 DP - 2017 May TI - Novel two-step derivation method for the synchronous analysis of inherited metabolic disorders using urine. PG - 1961-1968 LID - 10.3892/etm.2017.4167 [doi] AB - The aim of the present study was to conduct preliminary clinical screening and monitoring using a novel two-step derivatization process of urine in five categories of inherited metabolic disease (IMD). Urine samples (100 microl, containing 2.5 mmol/l creatinine) were taken from patients with IMDs. The collected urine was then treated using a two-step derivatization method (with oximation and silylation at room temperature), where urea and protein were removed. In the first step of the derivatization, alpha-ketoacids and alpha-aldehyde acids were prepared by oximation using novel oximation reagents. The second-step of the derivatization was that residues were silylated for analysis. Urine samples were examined using gas chromatography/mass spectrometry (GC/MS) and a retention time-locking technique. The simultaneous analysis and identification of >400 metabolites in >130 types of IMD was possible from the GC/MS results, where the IMDs included phenylketonuria, ornithine transcarbamylase deficiency, neonatal intrahepatic cholestasis caused by citrin deficiency, beta-ureidopropionase deficiency and mitochondrial metabolic disorders. This method was demonstrated to have good repeatability. Considering alpha-ketoglutarate (alpha-KG) as an example, the relative standard deviations (RSDs) of the alpha-KG retention time and peak area were 0.8 and 3.9%, respectively, the blank spiked recovery rate was between 89.6 and 99.8%, and the RSD was