MWCNTs-solid phase extraction combined with ultra-high performance liquid chromatography-tandem mass spectrometry for the determination of eleven organophosphorus pesticides in river water

ABSTRACT

A method for simultaneous determination of 11 organophosphorus pesticides residues in river water by MWCNTs-solid phase extraction combined with ultra-high performance liquid chromatography/tandem mass spectrometry was developed. After centrifugation and filtration, the target pesticides were enriched with MWCNTs-SPE cartridge. Then the pesticides adsorbed on MWCNTs were eluted with ethyl acetate and dichloromethane, the eluent was dried-up under nitrogen flow and the residue was dissolved in methanol-water (1:1, v/v) as sample solution. The separation was accomplished on a C18 column with the mobile phase consisting of methanol and 0.1% formic acid at 0.20 mL/min in gradient elution. The pesticides were detected in multiple reaction monitoring mode by a triple quadruple mass spectrometer. Good linearities were obtained within 1–200 ng/L, with the correlation coefficients greater than 0.998. The detection and quantification limits were in the ranges of 0.02–1.00 ng/L and 0.07–3.33 ng/L, respectively. The recoveries and relative standard deviations were in the range of 88.3–124.9% and 0.12–20.5%, respectively. The method has been successfully applied to the detection of 34 urban river water samples from Chengdu, China and 7 organophosphorus pesticides were detected with the concentrations of 0.32–211 ng/L.

KEYWORDS:

• Organophosphorus pesticides
• multi-walled carbon nanotubes
• ultra-high performance liquid chromatography-tandem mass spectrometry
• river water

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by Sichuan Center for Disease Control and Prevention under Grant (No. ZX201510).