Simultaneous determination of base/neutral and acid herbicides in natural water at the part per trillion level

摘要: A new method for the simultaneous identification and quantification of base/neutral acidic pesticides at a low nanogram per liter concentration level in natural waters is presented. The includes enrichment compounds by solid phase extraction on graphitized carbon black, followed sequential elution pesticides. Identification performed with HPLC-ESI-MS. This procedure involves passing 1 L ground water 2 drinking samples through 0.5 g black (GCB) cartridge. conventional 4.6-mm-i.d. reversed LC C-18 operating mL min−1 flow mobile was used to chromatograph analytes. 100 μL column effluent diverted ESI source. source operated positive ion mode negative-ion acid For analyte considered, response mass detector linearly related amount analytes injected between 5 250 ng. In all cases, recoveries were better than 90%. limit detection (signal-to-noise ratio=3) considered estimated be about 3–10 ng L−1.