Direct determination of methyl parathion insecticide in rice samples by headspace solid-phase microextraction-gas chromatography-mass spectrometry

作者：da Silva Darlan Ferreira; Paiva Silva Francisco Eduardo; Silva Fernanda Gabrielle S; Nunes Gilvanda Silva^*; Badea Mihaela

来源：Pest Management Science, 2015, 71(11): 1497-1502.

DOI：10.1002/ps.3953

• solid-phase microextraction
• methyl parathion
• organophosphorus pesticides
• GC
• MS

BACKGROUNDThe organophosphorus insecticides, especially those based on methyl parathion as active principle, have been used extensively in the protection of rice in MaranhAo State, in the north-east of Brazil. This paper describes the optimisation of a solid-phase microextraction (SPME) procedure in confined atmosphere (headspace, HS) for the determination of methyl parathion in rice organic samples by gas chromatography with mass spectrometry detection (GC/MS).
RESULTSThe proposed HS-SPME-GC/MS method has been shown to be appropriate for direct analysis of the insecticide in polished rice, with satisfactory results for the following parameters: linearity (correlation coefficient 0.9985), sensitivity (LOD and LOQ of 0.026 and 0.078 mu gkg(-1) respectively), precision (coefficients of variation between 6.1 and 22.4%) and accuracy (recoveries varying from 73.2 to 90.0%). Although the efficiency of the proposed GC/MS does not differ statistically (P < 0.05) from the conventional GC/NPD method, given its low cost, speed and also the fact that a minimum volume of toxic effluent is generated, this method can be considered an on-line procedure based on green chemistry.
CONCLUSIONSThus, the analytical methodology satisfies the minimum requirements for control of residues of such insecticides in rice samples destined for human consumption.

• 出版日期2015-11