Simultaneous determination of parathion, malathion, diazinon, and pirimiphos methyl in dried medicinal plants using solid-phase microextraction fibre coated with single-walled carbon nanotubes.
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 (r(2) ≥ 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 (r(2) ≥ 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.
Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences, Tehran 14174, Iran.
Reza
R
Ahmadkhaniha
Nasrin
N
Samadi
Mona
M
Salimi
Parisa
P
Sarkhail
Noushin
N
Rastkari
D002138:Calibration; D003976:Diazinon / Q000032:analysis*; D004129:Dimethylpolysiloxanes / Q000737:chemistry; D057230:Limit of Detection; D008294:Malathion / Q000032:analysis*; D036103:Nanotechnology / Q000379:methods*; D037742:Nanotubes, Carbon / Q000737:chemistry*; D009943:Organophosphorus Compounds / Q000737:chemistry; D009946:Organothiophosphorus Compounds / Q000032:analysis*; D010278:Parathion / Q000032:analysis*; D010575:Pesticides / Q000737:chemistry; D010946:Plants, Medicinal; D015203:Reproducibility of Results; D052617:Solid Phase Microextraction; D013696:Temperature
D004129:Dimethylpolysiloxanes; D037742:Nanotubes, Carbon; D009943:Organophosphorus Compounds; D009946:Organothiophosphorus Compounds; D010575:Pesticides; C014153:pirimiphos methyl; D010278:Parathion; C013830:baysilon; D008294:Malathion; D003976:Diazinon