title: Development of the space-resolved solid-phase microextraction technique and its application to biological matrices.
abstract: To facilitate rapid in situ analyte monitoring within heterogeneous samples, a space-resolved solid phase microextraction (SR-SPME) technique was developed that utilized miniaturized segmented fibers. Initially, a multilayered agarose gel was used to determine the effects of diffusion-based mass transfer and fiber dimension on the space-resolving capability of SPME. For diazepam within agarose gel, the SR-SPME limit of detection was 2.5 ng/mL, with a linear dynamic range up to 500 ng/mL. The efficacy of the SR-SPME technique was further evaluated within diverse biological matrices (onion bulb, fish muscle, and adipose tissues) containing stratified pharmaceutical analytes. Empirically, the results agreed well with established techniques such as microdialysis and liquid extraction, but SR-SPME was simpler to implement, displayed higher spatial resolution, and was more cost-effective than traditional approaches. Additionally, the segmented design of the SPME fibers and stepwise desorption protocols offer potential advantages within high throughput applications.
authors.affiliation: Department of Chemistry, University of Waterloo, Ontario, N2L 3G1, Canada.
authors.forename: Xu
authors.initials: X
authors.lastname: Zhang
authors.forename: Jibao
authors.initials: J
authors.lastname: Cai
authors.forename: Ken D
authors.initials: KD
authors.lastname: Oakes
authors.forename: François
authors.initials: F
authors.lastname: Breton
authors.forename: Mark R
authors.initials: MR
authors.lastname: Servos
authors.forename: Janusz
authors.initials: J
authors.lastname: Pawliszyn
mesh_terms: D000273:Adipose Tissue / Q000737:chemistry; D000818:Animals; D002138:Calibration; D003975:Diazepam / Q000032:analysis; D004058:Diffusion; D005399:Fishes; D005782:Gels / Q000737:chemistry; D009132:Muscles / Q000737:chemistry; D019697:Onions / Q000737:chemistry*; D004364:Pharmaceutical Preparations / Q000032:analysis*; D012680:Sensitivity and Specificity; D052617:Solid Phase Microextraction / Q000191:economics / Q000379:methods*
chemical_list: D005782:Gels; D004364:Pharmaceutical Preparations; D003975:Diazepam