title: Analytical derivatization-a tool for determination of orotic acid.
abstract: Derivatization of orotic acid (OA) into various forms (trimethylsilylderivate, alkyl ester and per-methylated derivate) and their evaluation by GC/MS is described. The tested approach includes ion-exchange SPE clean-up, evaporation and chemical reaction with different types of derivatization agents (N,O-bis-(trimethylsilyl)trifluoroacetamide with trimethylchlorosilane, butanol with acetylchloride and ethereal solution of diazomethane). Derivate originated in the reaction with diazomethane was used for determination of urinary orotic acid by GC/MS. Detection limit of 0.28 micromol l(-1) was reached using the ion 82 m/z in single ion monitoring (SIM) mode. Linearity of the method was tested within the range of 3.4-2503.4 micromol l(-1) covering physiological and pathological levels of orotic acid in urine sample. Recoveries were within the range 93.7-110.6%. Application of the method on the patient with defect of ornithine transcarbamylase (OTC) was demonstrated as well.
authors.affiliation: Department of Analytical Chemistry, Palacký University, Tr. Svobody 8, 771 46 Olomouc, Czech Republic. renata.huskova@email.cz
authors.forename: Renata
authors.initials: R
authors.lastname: Husková
authors.forename: Petr
authors.initials: P
authors.lastname: Barták
authors.forename: Lubomír
authors.initials: L
authors.lastname: Cáp
authors.forename: David
authors.initials: D
authors.lastname: Friedecký
authors.forename: Tomás
authors.initials: T
authors.lastname: Adam
mesh_terms: D002853:Chromatography, Liquid; D003978:Diazomethane / Q000737:chemistry; D004952:Esters; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D008745:Methylation; D009963:Orotic Acid / Q000032:analysis* / Q000737:chemistry; D015203:Reproducibility of Results; D014297:Trimethylsilyl Compounds / Q000737:chemistry
chemical_list: D004952:Esters; D014297:Trimethylsilyl Compounds; D003978:Diazomethane; D009963:Orotic Acid