The Impact of Pesticides - Academy Publish

extracting the pesticides from the fatty samples. The prepared samples wereanalysed with GC–MS in the selected ion monitoring mode (SIM) using one targetand two qualitative ions for each analyte. Chlorpyrifos-d 10 was used as an internalstandard. The lowest limit of detection was 0.3 µg kg -1 for some pesticides. Therecoveries and relative standard deviations (RSDs) were checked by spikinguntreated samples with pesticides at 0.05, 0.1 and 0.2 mg kg -1 . The averagerecoveries of most pesticides were from 62.6 to 107.8%. The precision valuesexpressed as RSD were all 20.5% (n = 6). Good linearity (r 2 ≥ 0.99) was observedbetween 0.05 and 1.5 µg mL -1 (Wu et al., 2011).Zhang et al. compared PLE, selective pressurized extraction (SPLE), soxhlet andultrasonic and heating extraction methods for the simultaneous extraction and cleanupof PBDEs and PCBs in sheep liver tissue samples followed by gaschromatography–mass spectrometry (GC–MS). Overall the mean percentagerecoveries for all target chemicals using SPLE were 86–103% (n = 3, SD < 9%),and compared favourably with the Soxhlet (63–109%, n = 3, SD < 8%), off-linePLE (82–104%, n = 3, SD < 18%), ultrasonic (86–99%, n = 3, SD < 11%) andheating (72–102%, n = 3, SD < 21%) extraction methods. The limits of detection ofthe proposed method were 5–96 pg g −1 and 2–29 pg g −1 for the different PBDE andPCB chemicals studied, respectively. The outputs of the proposed method werelinear over the range from 0.02 to 30 ng g −1 , for all PCB and PBDE congenersexcept for PBDE 100 and 153 (0.05–30 ng g −1 ) and PBDE 183 (0.1–30 ng g −1 ). Themethod was successfully applied to sheep liver samples for the determination of thetarget PBDE and PCB compounds (Zhang et al., 2011).The feasibility of different extraction procedures (PLE, QuEChERS, SPE, andSPME) was tested and compared by Blasco et al. (2011) for the determination of 12organophosphorus and carbamates insecticides in honey samples. The main aim ofthis work was to maximise the sensitivity of pesticides and to minimise the presenceof interfering compounds in the extract. All curves were linear in the range fromCC β to 1000× CC β for the four extraction methods (three orders of magnitude).Detection capabilities (CC β ) were 0.007–0.595 mg kg −1 with PLE, 0.024–1.155 mgkg −1 with QuEChERS, 0.010–0.646 mg kg −1 with SPE, and 0.001–0.060 mg kg −1with SPME. All the target compounds could be recovered by any of the methods, ata CC β fortification level ranged from 28 to 90% for the SPME. In comparison, thePLE method was the most efficient extraction method with recoveries from 82 to104%. It was followed by the QuEChERS method with recoveries between 78 and101% and the SPE method with recoveries between 72 and 100%. The repeatabilityexpressed as relative standard deviation (RSDs) was below 20% for all thepesticides by any of the tested extraction methods. Results obtained applying thefour extraction techniques to real honey samples are analogous.Many applications have been described in the literature using pressurized liquidextraction systems applied to organochlorine pesticide extraction from animalinternal organs, adipose tissue (Saito et al., 2004), eggs (Wang et al., 2005), milk(Brutti et al., 2010) and shellfish (Buisson et al., 2008).AcademyPublish.org - The Impact of Pesticides366