Abstract

In this research work we have tried to emphasis that the synergistic approach is required wherein during method development sample processing and instrument i.e., mass spectrometershall be evaluated in synchronized manner to get the best possible combination of processing technique and instrument model to get a method with no or minimal matrix effect. To perform this research work polar molecule niacin is considered as a model drug to evaluate the synergistic approach. Plasma was treated with three different conventional sample preparation procedures (PPT, LLE and SPE) and samples processed with the three methodology were then analyzed on three different instrument models of AB Sciex i.e., API-3000, API-3200, API-4000. Except for type of sample processing technique and instrument model, rest of the parameters like aliquot volume, internal standard working solution volume and chromatographic conditions were kept constant to avoid contribution of these factors due to these variables. Samples were analyzed using Inertsil® CN-3 as an analytical column and mobile phase consist of acetonitrile - solution-1(0.002% formic acid in water, v/v) in the ratio of 70:30, v/v. Result evidently showed that matrix effect was minimized through SPE technique over LLE technique and behavior of the co-elute matrix also changed significantly with ion-source design of the mass spectrometer. Consequently, the development result clearly showed that matrix effect was nullified by samples prepared by SPE technique and analyzed on API-3000. Results obtained from API- 3000 and API-4000 models were also comparable in terms of matrix effect. API-3000 in combination with solid phase extraction procedure was selected to further validate the method as API-4000 showed charge competition of internal standard. Overall, the results indicate that extraction procedure plays a crucial role to control matrix effect but to get the best result LC have to be coupled with mass spectrometer with proper ion source.

Keywords: Matrix effect; Process efficiency; Sample extraction technique; LC-MS/MS; Instrument model