title: A new on-line sample preparation system for the liquid chromatography/time-of-flight mass spectrometry simultaneous analysis of pesticides in river water.
abstract: Current on-line solid-phase extraction methods combined with HPLC for shortening the clean-up operation are not suitable for simultaneously detecting compounds that have a wide variety of hydrophobicities. To solve these problems, we designed a new on-line sample preparation system. The system consists of an eluting pump, a mixing TEE connector, a 10-port 2-position valve and a solid-phase extraction precolumn. The eluate from the precolumn is diluted with a weak solvent from the HPLC at the TEE connection to load low hydrophobic compounds onto the analytical column. The proposed on-line sample preparation system was successfully applied to the simultaneous analysis of 21 pesticides in river water using LC/TOF-MS. In this method, the recoveries from river water samples were 67 to 126% (mean 83%), the reproducibility (CV%) was in the range from 1.1 to 11% (mean 5.6%), the calibration curve was linear in the range from 1 ppb to 500 ppb (r > 0.999) and the detection limits (S/N = 3) were in the range from 0.0034 ppb (daimuron) to 3.3 ppb (oxine-copper).
authors.affiliation: Nihon Waters K. K., Shinagawa, Tokyo, Japan. hideki.sasaki@waters.com
authors.forename: Hideki
authors.initials: H
authors.lastname: Sasaki
authors.forename: Jun
authors.initials: J
authors.lastname: Yonekubo
authors.forename: Kazuichi
authors.initials: K
authors.lastname: Hayakawa
mesh_terms: D001331:Automation; D002138:Calibration; D002623:Chemistry Techniques, Analytical / Q000379:methods; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D002853:Chromatography, Liquid / Q000379:methods*; D004867:Equipment Design; D013058:Mass Spectrometry / Q000379:methods*; D004364:Pharmaceutical Preparations / Q000032:analysis; D015203:Reproducibility of Results; D045483:Rivers; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000032:analysis*; D014881:Water Supply
chemical_list: D004364:Pharmaceutical Preparations; D014874:Water Pollutants, Chemical