Simultaneous Determination of Parathion, Malathion, Diazinon, and Pirimiphos Methyl in Dried Medicinal Plants Using Solid-Phase Microextraction Fibre Coated with Single-Walled Carbon Nanotubes

Abstract EN

A reliable and sensitive headspace solid-phase microextraction gas chromatography-mass spectrometry method for simultaneous determination of different organophosphorus pesticides in dried medicinal plant samples is described.

The analytes were extracted by single-walled carbon nanotubes as a new solid-phase microextraction adsorbent.

The developed method showed good performance.

For diazinon and pirimiphos methyl calibration, curves were linear (r2≥0.993) over the concentration ranges from 1.5 to 300 ng g−1, and the limit of detection at signal-to-noise ratio of 3 was 0.3 ng g−1.

For parathion and malathion, the linear range and limit of detection were 2.5–300 (r2≥0.991) and 0.5 ng g−1, respectively.

In addition, a comparative study between the single-walled carbon nanotubes and a commercial polydimethylsiloxane fibre for the determination of target analytes was carried out.

Single-walled carbon nanotubes fibre showed higher extraction capacity, better thermal stability (over 350∘C), and longer lifespan (over 250 times) than the commercial polydimethylsiloxane fibre.

The developed method was successfully applied to determine target organophosphorus pesticides in real samples.