Pervasive Gabapentin Interference in the LC-MS/MS Analysis of Amphetamine. (15th October 2019)

• Record Type: Journal Article
• Authors: Shugarts, Sarah B
• Is Part Of: Journal of applied laboratory medicine. Volume 2:Number 4(2018)
• Page Start: 527
• Page End: 534
• Publication Date: 2019-10-15
• Subjects: Clinical chemistry -- Periodicals; Diagnosis, Laboratory -- Periodicals; 616.0756
• DOI: 10.1373/jalm.2017.024117
• Languages: English
• ISSNs: 2576-9456

Abstract

Abstract: Background: An LC-MS/MS urine confirmation assay was developed using a "dilute and shoot" sample preparation method that was subject to interference arising from gabapentin column overload in approximately 4% of patient samples, leading to interference in amphetamine analysis. Methods: The initial analysis method used dilute and shoot sample preparation followed by LC-MS/MS analysis. The improved assay used solid-phase extraction sample preparation followed by LC-MS/MS analysis. Results: The improved assay using solid-phase extraction and alternative chromatographic conditions resolved the gabapentin interference in amphetamine analysis. Conclusions: This experience illustrates the importance of thorough knowledge of likely comedications in a patient population and these drugs' elimination mechanisms. Laboratorians should be aware of the phenomenon of mass effect LC-MS/MS interference, in addition to the more common LC-MS/MS interferences caused by matrix effects and isobaric compounds.