title: Stir bar sorptive extraction and comprehensive two-dimensional gas chromatography coupled to high-resolution time-of-flight mass spectrometry for ultra-trace analysis of organochlorine pesticides in river water.
abstract: A method for the determination of ultra-trace amounts of organochlorine pesticides (OCPs) in river water was developed by using stir bar sorptive extraction (SBSE) followed by thermal desorption and comprehensive two-dimensional gas chromatography coupled to high-resolution time-of-flight mass spectrometry (SBSE-TD-GC×GC-HRTOF-MS). SBSE conditions such as extraction time profiles, phase ratio (β: sample volume/polydimethylsiloxane (PDMS) volume), and modifier addition, were examined. Fifty milli-liter sample including 10% acetone was extracted for 3 h using stir bars with a length of 20 mm and coated with a 0.5 mm layer of PDMS (PDMS volume, 47 μL). The stir bar was thermally desorbed and subsequently analyzed by GC×GC-HRTOF-MS. The method showed good linearity over the concentration range from 50 to 1000 pg L(-1) or 2000 pg L(-1) for all analytes, and the correlation coefficients (r(2)) were greater than 0.9903 (except for β-HCH, r(2)=0.9870). The limit of detection (LOD) ranged from 10 to 44 pg L(-1). The method was successfully applied to the determination of 16 OCPs at pg L(-1) to ng L(-1) in river water. The results agree fairly well with the values obtained by a conventional liquid-liquid extraction (LLE)-GC-HRMS (selected ion monitoring: SIM) method using large sample volume (20 L). The method also allows screening of non-target compounds, e.g. pesticides and their degradation products, polyaromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and pharmaceuticals and personal care products (PPCPs) and metabolites in the same river water sample, by using full spectrum acquisition with accurate mass in GC×GC.
authors.affiliation: GERSTEL K.K., 2-13-18 Nakane, Meguro-ku, Tokyo 152-0031, Japan. nobuo ochiai@gerstel.co.jp
authors.forename: Nobuo
authors.initials: N
authors.lastname: Ochiai
authors.forename: Teruyo
authors.initials: T
authors.lastname: Ieda
authors.forename: Kikuo
authors.initials: K
authors.lastname: Sasamoto
authors.forename: Yoshikatsu
authors.initials: Y
authors.lastname: Takazawa
authors.forename: Shunji
authors.initials: S
authors.lastname: Hashimoto
authors.forename: Akihiro
authors.initials: A
authors.lastname: Fushimi
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Tanabe
mesh_terms: D005591:Chemical Fractionation / Q000379:methods*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006843:Hydrocarbons, Chlorinated / Q000032:analysis*; D016014:Linear Models; D010575:Pesticides / Q000032:analysis*; D011084:Polycyclic Aromatic Hydrocarbons; D015203:Reproducibility of Results; D045483:Rivers / Q000737:chemistry*; D012680:Sensitivity and Specificity; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D006843:Hydrocarbons, Chlorinated; D010575:Pesticides; D011084:Polycyclic Aromatic Hydrocarbons; D014874:Water Pollutants, Chemical