Analysis of insecticides in honey by liquid chromatography-ion trap-mass spectrometry: comparison of different extraction procedures.

The feasibility of different extraction procedures was tested and compared for the determination of 12 organophosphorus and carbamates insecticides in honey samples. In this sense, once the samples were pre-treated - essentially dissolved in hot water by stirring - and before they could be analyzed by liquid chromatography-ion trap-second stage mass spectrometry (LC-MS(2)), four different approaches were studied for the extraction step: QuEChERS, solid-phase extraction (SPE), pressurized liquid extraction (PLE) and solid-phase microextraction (SPME). The main aim of this work was to maximise the sensitivity of pesticides and to minimise the presence of interfering compounds in the extract. All pesticides were linear in the range from CC(β) to 1000× CC(β) for the four extraction methods (three orders of magnitude). Detection capabilities (CC(β)) were 0.024-1.155 mg kg(-1) with QuEChERS, 0.010-0.646 mg kg(-1) with SPE, 0.007-0.595 mg kg(-1) with PLE, and 0.001-0.060 mg kg(-1) with SPME. All the target compounds could be recovered by any of the methods, at a CC(β) fortification level ranged from 28 to 90% for the SPME. In comparison, the PLE method was the most efficient extraction method with recoveries from 82 to 104%. It was followed by the QuEChERS method with recoveries between 78 and 101% and the SPE method with recoveries between 72 and 100%. The repeatability expressed as relative standard deviation (RSDs) was below 20% for all the pesticides by any of the tested extraction methods. Results obtained applying the four extraction techniques to real honey samples are analogous.