PMID- 16106856 OWN - NLM STAT- MEDLINE DCOM- 20050912 LR - 20190720 IS - 0021-9673 (Print) IS - 0021-9673 (Linking) VI - 1085 IP - 1 DP - 2005 Aug 26 TI - Simultaneous determination of creatinine, creatine, and UV-absorbing amino acids using dual-mode gradient low-capacity cation-exchange chromatography. PG - 110-6 AB - A simple and versatile cation-exchange chromatography technique for the simultaneous determination of urinary creatinine (Cre), creatine (Crn), methionine (Met), tyrosine (Tyr), phenylalanine (Phe), histidine (His), and tryptophan (Trp) was developed. A novel low-capacity cation-exchange column packed with a newly developed sulfoacylated hypercross-linked macroreticular polystyrene-divinylbenzene resin, referred to as TMR-A/75 (capacity: 75 microequiv/column), was successfully used with a binary dual-mode gradient eluting system. Two solvents, (A) 25 mM phosphoric acid-methanol (30:70, v/v) and (B) 25 mM disodium hydrogenphosphate-methanol (30:70, v/v) were pumped through the column by programming solvent delivery ratios as 0 to 5 min: A-B (55:45, pH 3.6); 5-21 min: A-B (49:51, pH 5.3); and 21-35 min: A-B (55:45, pH 3.6). The flow rate was simultaneously time-programmed to be 0.6 mL/min from 0 to 19 min and to be 1.0 mL/min from 19 to 35 min. This eluting system could permit the use of the UV detection at 210 nm. The analytes, Crn, Met, Tyr, His, Cre, Phe, and Trp, were well separated in this order in 27 min with minimum resolution of approximately 2, and the cycle time was about 35 min. Retention time of each analyte was very reproducible with relative standard deviations (RSDs) between 0.05 and 0.38% (n = 5). The peak area responses were also reproducible with RSDs between 0.74 and 2.24% (n = 5). Calibration lines based on area data were linear from 1 to 1000 microM with r2 values of 0.9998 (Crn), 0.9998 (Met), 0.9999 (Tyr), 0.9999 (His), 1.0000 (Cre), 1.0000 (Phe), and 0.9999 (Trp). The method was applicable to the screening and/or chemical diagnosis of inherited metabolic disorders such as phenylketonuria (PKU), tyrosinemia, and Lowe syndrome. The creatinine ratios of diagnostic markers (microM/microM Cre) were easily determined. The Phe/Cre ratios for five urines from patients with PKU ranged from 0.162 to 0.521, and the Tyr/Cre ratio for tyrosinemia was 0.147. The ratios of Tyr/Cre, Phe/Cre, and Trp/Cre for Lowe syndrome were 0.497, 0.321, and 0.495, respectively. In contrast, the creatinine ratios for healthy newborns showed one digit lower than those for patients did. The developed method is very practical and can provide useful information and results for the clinical or biomedical researches with low analytical run costs. FAU - Yokoyama, Yukio AU - Yokoyama Y AD - Department of Analytical Chemistry, Faculty of Engineering, Yokohama National University, Tokiwadai, Hodogaya, Yokohama 240-8501, Japan. yokyuk@ynu.ac.jp FAU - Tsuji, Sachiyo AU - Tsuji S FAU - Sato, Hisakuni AU - Sato H LA - eng PT - Comparative Study PT - Journal Article PL - Netherlands TA - J Chromatogr A JT - Journal of chromatography. A JID - 9318488 RN - 0 (Amino Acids) RN - 0 (Cation Exchange Resins) RN - 0 (Polystyrenes) RN - AYI8EX34EU (Creatinine) RN - MU72812GK0 (Creatine) SB - IM MH - Amino Acids/*analysis/urine MH - Cation Exchange Resins MH - Chromatography, Ion Exchange/instrumentation/*methods MH - Creatine/*analysis/urine MH - Creatinine/*analysis/urine MH - Humans MH - Hydrogen-Ion Concentration MH - Infant, Newborn MH - Phenylketonurias/diagnosis/urine MH - Polystyrenes/chemistry MH - Reproducibility of Results MH - Sensitivity and Specificity MH - Spectrophotometry, Ultraviolet/*methods MH - Temperature EDAT- 2005/08/19 09:00 MHDA- 2005/09/13 09:00 CRDT- 2005/08/19 09:00 PHST- 2005/08/19 09:00 [pubmed] PHST- 2005/09/13 09:00 [medline] PHST- 2005/08/19 09:00 [entrez] AID - S0021-9673(05)00099-3 [pii] AID - 10.1016/j.chroma.2005.01.030 [doi] PST - ppublish SO - J Chromatogr A. 2005 Aug 26;1085(1):110-6. doi: 10.1016/j.chroma.2005.01.030.