title: Method of applying internal standard to dried matrix spot samples for use in quantitative bioanalysis.
abstract: A novel technique is presented that addresses the issue of how to apply internal standard (IS) to dried matrix spot (DMS) samples that allows the IS to integrate with the sample prior to extraction. The TouchSpray, a piezo electric spray system, from The Technology Partnership (TTP), was used to apply methanol containing IS to dried blood spot (DBS) samples. It is demonstrated that this method of IS application has the potential to work in practice, for use in quantitative determination of circulating exposures of pharmaceuticals in toxicokinetic and pharmacokinetic studies. Three different methods of IS application were compared: addition of IS to control blood prior to DBS sample preparation (control 1), incorporation into extraction solvent (control 2), and the novel use of TouchSpray technology (test). It is demonstrated that there was no significant difference in accuracy and precision data using these three techniques obtained using both manual extraction and direct elution.
authors.affiliation: Platform Technology and Science, Drug Metabolism and Pharmacokinetics, GlaxoSmithKline Research and Development, Ware, Hertfordshire, United Kingdom. Paul.2.Abu-Rabie@gsk.com
authors.forename: Paul
authors.initials: P
authors.lastname: Abu-Rabie
authors.forename: Philip
authors.initials: P
authors.lastname: Denniff
authors.forename: Neil
authors.initials: N
authors.lastname: Spooner
authors.forename: Jan
authors.initials: J
authors.lastname: Brynjolffssen
authors.forename: Paul
authors.initials: P
authors.lastname: Galluzzo
authors.forename: Giles
authors.initials: G
authors.lastname: Sanders
mesh_terms: D000082:Acetaminophen / Q000097:blood*; D000634:Aminoquinolines / Q000097:blood*; D002851:Chromatography, High Pressure Liquid; D059788:Dried Blood Spot Testing / Q000295:instrumentation / Q000379:methods* / Q000592:standards*; D006801:Humans; D013058:Mass Spectrometry; D000432:Methanol / Q000737:chemistry; D012680:Sensitivity and Specificity
chemical_list: D000634:Aminoquinolines; D000082:Acetaminophen; C080436:8-aminoquinoline; D000432:Methanol