title: Application of liquid-phase microextraction and gas chromatography-mass spectrometry for the determination of polychlorinated biphenyls in blood plasma.
abstract: This study investigated the feasibility of applying liquid-phase microextraction combined with gas chromatography-mass spectrometry (GC-MS) to determine polychlorinated biphenyls (PCBs) in blood plasma. An efficient and simple extraction technique has been developed for the enrichment of PCBs from human blood plasma samples using single-step liquid-phase microextraction (LPME) in conjunction with a hollow fibre membrane (HFM). An eight PCB congener mixture was spiked into 2.5 ml of blood plasma, and the solution was then adjusted to pH 10.5 with a salinity of 20% (w/v) prior to making the total volume to 5 ml with ultrapure water. The porous HFM, filled with 3 microl of organic solvent, was then immersed into the solution, which was continuously agitated at 700 rpm for 30 min. Extract (1 microl) containing the pre-concentrated analytes was then injected into a GC-MS without further pre-treatment. Using an optimised extraction procedure, a large enrichment factor of the analytes, i.e. up to 241-fold was achieved in 30 min. The procedure resulted in a relative standard deviation of < 11% (n = 6), and a linear calibration range from 2.5 to 150 microg/l (r > 0.999), and detection limits between 0.07 and 0.94 microg/l, respectively. To demonstrate the feasibility of the procedure, PCB concentrations were determined in actual blood samples collected from the local population in Singapore using the optimised LPME technique.
authors.affiliation: Department of Chemistry, 3 Science Drive 3, National University of Singapore, Singapore 117543, Singapore.
authors.forename: Chanbasha
authors.initials: C
authors.lastname: Basheer
authors.forename: Hian Kee
authors.initials: HK
authors.lastname: Lee
authors.forename: Jeffrey Philip
authors.initials: JP
authors.lastname: Obbard
mesh_terms: D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D011078:Polychlorinated Biphenyls / Q000097:blood*; D012965:Sodium Chloride / Q000737:chemistry; D012997:Solvents / Q000737:chemistry
chemical_list: D012997:Solvents; D012965:Sodium Chloride; D011078:Polychlorinated Biphenyls