title: High-throughput polymer monolith in-tip SPME fiber preparation and application in drug analysis.
abstract: BACKGROUND
  A simple, low-cost and reproducible automated procedure has been developed to prepare in-tip solid-phase microextraction (SPME) fibers coated with polymer monoliths using a photopolymerization technique. Up to 96 fibers were prepared at one time using a polymerization mixture consisting of ethylene glycol dimethacrylate, dimethoxy-α-phenylacetophenone and 1-decanol.
  
  
  RESULTS
  The optimization procedures that affected polymer morphology, such as compositions of the crosslinkers and porogens, polymerization time and fiber thickness as well as extraction efficiency of the immobilized Oasis hydrophilic-lipophilic-balanced extraction sorbent were investigated. Also, the reproducibility of automated in-tip SPME fiber preparation, as well as sample process parameters, such as sample extraction and desorption volumes, are discussed.
  
  
  CONCLUSIONS
  The performance of the polymer monoliths in-tip SPME assessed with a model drug compound from clinical studies and a head-to-head comparison using in-tip SPME and conventional SPE clearly demonstrated that the SPME is a feasible approach for routine drug analysis in the pharmaceutical industry.
authors.affiliation: Department of Drug Metabolism, Merck Research Laboratories, West Point, PA 19486, USA. wei_xie@merck.com
authors.forename: Wei
authors.initials: W
authors.lastname: Xie
authors.forename: Wayne
authors.initials: W
authors.lastname: Mullett
authors.forename: Janusz
authors.initials: J
authors.lastname: Pawliszyn
mesh_terms: D001381:Azepines / Q000032:analysis / Q000097:blood / Q000737:chemistry; D057166:High-Throughput Screening Assays / Q000379:methods*; D006801:Humans; D007093:Imidazoles / Q000032:analysis / Q000097:blood / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D004364:Pharmaceutical Preparations / Q000032:analysis* / Q000097:blood; D055668:Photochemical Processes; D011108:Polymers / Q000737:chemistry*; D015203:Reproducibility of Results; D052617:Solid Phase Microextraction / Q000379:methods*
chemical_list: D001381:Azepines; D007093:Imidazoles; D004364:Pharmaceutical Preparations; D011108:Polymers; C525458:telcagepant