Determination of memantine in human plasma by GC using negative ion chemical ionization MS detection after derivatization with a new reagent

We describe a method for the determination of memantine in plasma by use of the derivatization reagent o-(pentafluorobenzyloxycarbonyl)-benzoyl chloride. Memantine can be quantitatively analyzed down to 49 pg per mL of plasma using a 250 mu L sample and negative ion chemical ionisation mass spectrometry (GC-NICI-MS). Plasma samples were made alkaline with carbonate buffer and extracted with n-hexane. The extracts were treated with reagent solution for 20 min, concentrated, and submitted to GC-NICI-MS. The method is rapid because extraction and derivatization occur in one single step. Amantadine is used as an internal standard. The utility and robustness of the assay is demonstrated by giving data on specificity, linearity, accuracy and precision, benchtop stability, freeze-thaw stability, autosampler stability, aliquot analysis, and prospective analytical batch size accuracy.