title: Investigation of different approaches to incorporating internal standard in DBS quantitative bioanalytical workflows and their effect on nullifying hematocrit-based assay bias.
abstract: Hematocrit (HCT)-based assay bias (composed of area and recovery bias) is an important contributing factor to the barriers that currently hinder the development and acceptance of dried blood spots (DBS) as a widely used quantitative bioanalytical sampling technique for regulatory studies. This article describes the evaluation of a practical internal standard spray addition technique, used prior to LC-MS/MS analysis, which is demonstrated to nullify the effect of recovery bias. To our knowledge, this is the first time a potential solution to HCT-based recovery bias has been investigated in detail and reported in the literature. This new technique is coupled with accurate volume DBS sampling, whole-spot extraction, and automated direct elution techniques to demonstrate a workflow that both nullifies HCT-based assay bias and the additional manual extraction burden associated with DBS analysis.
authors: †Bioanalytical Science and Toxicokinetics, Drug Metabolism and Pharmacokinetics, Platform Technologies and Sciences, GlaxoSmithKline Research and Development, Ware, SG12 0DP, United Kingdom.|‡Faculty of Engineering and Science, University of Greenwich, Medway Campus, Chatham Maritime, Kent ME4 4TB, United Kingdom.
authors: Paul
authors: P
authors: Abu-Rabie
authors: †Bioanalytical Science and Toxicokinetics, Drug Metabolism and Pharmacokinetics, Platform Technologies and Sciences, GlaxoSmithKline Research and Development, Ware, SG12 0DP, United Kingdom.
authors: Philip
authors: P
authors: Denniff
authors: †Bioanalytical Science and Toxicokinetics, Drug Metabolism and Pharmacokinetics, Platform Technologies and Sciences, GlaxoSmithKline Research and Development, Ware, SG12 0DP, United Kingdom.
authors: Neil
authors: N
authors: Spooner
authors: ‡Faculty of Engineering and Science, University of Greenwich, Medway Campus, Chatham Maritime, Kent ME4 4TB, United Kingdom.
authors: Babur Z
authors: BZ
authors: Chowdhry
authors: ‡Faculty of Engineering and Science, University of Greenwich, Medway Campus, Chatham Maritime, Kent ME4 4TB, United Kingdom.
authors: Frank S
authors: FS
authors: Pullen
mesh_terms: D002853:Chromatography, Liquid; D059788:Dried Blood Spot Testing; D006400:Hematocrit; D006801:Humans; D053719:Tandem Mass Spectrometry