Plasma som ersättning för serum i kontroller och kalibratorer. Undersökning av matriseffekter för analys av läkemedel med LC-MS/MS-teknik.

Abstract

For the current preparation of control and calibration samples for drug analysis with LC-MS/MS technique, serum is used where the fibrinogen has been precipitated with calcium chloride. Seeing as this may have an increased risk of ion suppression, it might be possible to use plasma where the fibrinogen has been removed by freeze/thaw-cycles instead. This study has been carried out to determine if and how there are any differences, such as ion suppression and enhancement, between the two matrices along with untreated plasma. The study has been performed along with two different methods for analysing drugs, such as neuroleptics and benzodiazepines. Post-column infusion was made for both methods and no appreciable ion suppression or enhancement were demonstrated for any of the three different matrices. Calibration curves were retrieved to determine differences between the matrices and these distinctions were marginal.