title: Optimization of an automated IS addition system for use in high-throughput quantitative DBS analysis.
abstract: BACKGROUND
  Automated DBS direct elution systems are available that incorporate IS spray modules which, unlike conventional IS addition via the extraction solvent, apply IS prior to DBS samples prior to extraction, allowing analyte and IS to be coextracted.
  
  
  RESULTS
  IS spray system parameters were optimized to identify the conditions that produced the best analytical performance in quantitative bioanalytical assays, without interfering with the integrity of the DBS sample prior to extraction.
  
  
  CONCLUSIONS
  LC-MS/MS method validations across four representative small molecule assays using the optimized IS spray conditions were demonstrated to produce analytical performance comparable to conventional methods of IS addition, demonstrating that the spray technique is a viable alternative.
authors.affiliation: Bioanalytical Science & Toxicokinetics, Drug Metabolism & Pharmacokinetics, Platform, Technologies & Sciences, GlaxoSmithKline, Research & Development, Ware, SG12 0DP, UK.|Faculty of Engineering & Science, University of Greenwich, Medway Campus, Chatham Maritime, Kent, ME4 4TB, UK.
authors.forename: Paul
authors.initials: P
authors.lastname: Abu-Rabie
authors.affiliation: Bioanalytical Science & Toxicokinetics, Drug Metabolism & Pharmacokinetics, Platform, Technologies & Sciences, GlaxoSmithKline, Research & Development, Ware, SG12 0DP, UK.
authors.forename: Neil
authors.initials: N
authors.lastname: Spooner
authors.affiliation: Faculty of Engineering & Science, University of Greenwich, Medway Campus, Chatham Maritime, Kent, ME4 4TB, UK.
authors.forename: Babur Z
authors.initials: BZ
authors.lastname: Chowdhry
authors.affiliation: Faculty of Engineering & Science, University of Greenwich, Medway Campus, Chatham Maritime, Kent, ME4 4TB, UK.
authors.forename: Frank S
authors.initials: FS
authors.lastname: Pullen
mesh_terms: D057205:Automation, Laboratory; D002853:Chromatography, Liquid / Q000379:methods*; D059788:Dried Blood Spot Testing / Q000379:methods*; D057166:High-Throughput Screening Assays / Q000592:standards*; D006801:Humans; D007553:Isotope Labeling; D012015:Reference Standards; D053719:Tandem Mass Spectrometry / Q000379:methods*