Determination of creatine and guanidinoacetate by GC-MS
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. 22 urines were kept at RT, 4 °C and − 30 °C for 15 days. MTBSTFA produces a single chromatographic p...
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Published in | Clinical biochemistry Vol. 42; no. 1; pp. 125 - 128 |
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Main Authors | , , , , , |
Format | Journal Article |
Language | English |
Published |
Elsevier Inc
2009
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Subjects | |
Online Access | Get full text |
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Summary: | 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.
22 urines were kept at RT, 4 °C and −
30 °C for 15 days.
MTBSTFA produces a single chromatographic peak in contrast with other derivatizing agents. Creatine concentration increases at room temperature (326% on average), and at 4 °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.
A modified GC-MS method has been validated and the conditions for preservation of the urine have been established. |
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ISSN: | 0009-9120 1873-2933 |
DOI: | 10.1016/j.clinbiochem.2008.10.001 |