Validation of an LC-MS/MS method for the determination of zopiclone, N-desmethylzopiclone and 2-amino-5-chloropyridine in whole blood and its application to estimate the original zopiclone concentration in stored specimens
2015 (English)In: International journal of legal medicine (Print), ISSN 0937-9827, E-ISSN 1437-1596, Vol. 129, no 2, 269-277 p.Article in journal (Refereed) Published
2-amino-5-chloropyridine (ACP) is a degradation product of zopiclone (ZOP) and may be formed when blood specimens are stored. ZOP instability in blood makes interpretation of concentrations difficult especially in cases of prolonged sample storage. This study investigated how ACP could be used to estimate the original concentration of ZOP in authentic samples. For that purpose, an analytical LC-MS/MS method for the quantitation of ACP, ZOP and the metabolite Ndesmethylzopiclone (NDZOP) in blood was validated. The method was then applied to investigate ACP formation, ZOP and NDZOP degradation in stored ZOP post-dosed authentic whole blood and two mathematical models were used to calculate the original concentration of ZOP. During storage, ACP was formed in amounts equimolar to the ZOP and NDZOP degradation. Results from samples in which ACP had been formed were used to test two models to estimate the original ZOP concentration. The correlation tests of the models showed strong correlations to the original ZOP concentration (r=0.960 and r=0.955) with p<0.01. This study showed that the equimolar degradation of ZOP and NDZOP to ACP could be used to estimate the original concentration of the unstable ZOP.
Place, publisher, year, edition, pages
Springer, 2015. Vol. 129, no 2, 269-277 p.
Degradation; Forensic toxicology; 2-amino-5-chloropyridine; Zopiclone; LC-MS/MS
Medical and Health Sciences Forensic Science
IdentifiersURN: urn:nbn:se:liu:diva-105820DOI: 10.1007/s00414-014-1049-2ISI: 000350032800007PubMedID: 25069820OAI: oai:DiVA.org:liu-105820DiVA: diva2:710925
The article title of this article was in Manuscript: LC-MS/MS determination of 2-amino-5-chloropyridine to estimate the original zopiclone concentration in stored whole blood.2014-04-082014-04-082016-03-23Bibliographically approved