Nonsteroidal anti-inflammatory drugs (NSAIDs) have been widely used as both over-the-counter and prescription drugs for the treatment of headache and cold symptoms. Therefore, NSAIDs have a high possibility becoming causative substances in poisoning cases and are often submitted for analysis in clinical and forensic practice. Because the majority of NSAIDs contain a carboxyl group, it is difficult to analyze them in their free form by gas chromatography-mass spectrometry (GC-MS). Therefore, we attempted detection of 18 NSAIDs as trimethylsilyl derivatives, and constructed a unique calibration-locking database using NAGINATA™ software with parameters such as the mass spectrum, retention time, and qualifier ion/target ion ratio (QT ratio) and a calibration curve. Diazepam-d 5 was used as an internal standard for construction of each calibration curve in the range of 0.05-10.0 μg/ml. We examined the applicability of the constructed database by analyzing whole blood samples spiked with 1 μg/ml each of the 18 NSAIDs. The drugs were extracted with dichloromethane or on a mixed-mode anion-exchange column (OASIS MAX™), subjected to GC-MS after incubation with N-methyl-N- (trimethylsilyl)trifluoroacetamide (MSTFA), and screened by the database. Among the 18 drugs examined, 15 and 17 drugs were successfully identified, respectively, and the absolute recoveries were 1.5-55.5% and 25.2-86.4%, respectively. The method was also applied to a case of suspected ibuprofen poisoning. Given that the established method showed significant improvement in the time required for data analysis, and qualitative and semiquantitative data were obtained without standard substances, we expect this new screening method using NAGINATA™to be very useful in confirming the presence of NSAIDs in blood in clinical and forensic cases.
All Science Journal Classification (ASJC) codes
- Pathology and Forensic Medicine
- Biochemistry, medical