Determination of creatine and guanidinoacetate by GC-MS: study of their stability in urine at different temperatures.
Clin Biochem
; 42(1-2): 125-8, 2009 Jan.
Article
em En
| MEDLINE
| ID: mdl-18992235
ABSTRACT
OBJECTIVES:
Evaluation of a GC-MS method using N-tert-butyldimethylsilyl-N-methyltrifluoroacetamide (MTBSTFA) as the silylating agent for GC-MS. Study of the stability of creatine and guanidinoacetate in urine. DESIGN ANDMETHODS:
22 urines were kept at RT, 4 degrees C and -30 degrees C for 15 days.RESULTS:
MTBSTFA produces a single chromatographic peak in contrast with other derivatizing agents. Creatine concentration increases at room temperature (326% on average), and at 4 degrees C (75%). However, detection decreases after freezing (-37%). Guanidinoacetate is stable, but decreases after freezing (-37%). Sonication before analysis is crucial to obtain repetitive results.CONCLUSIONS:
A modified GC-MS method has been validated and the conditions for preservation of the urine have been established.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Creatina
/
Glicina
/
Cromatografia Gasosa-Espectrometria de Massas
Idioma:
En
Ano de publicação:
2009
Tipo de documento:
Article