The Impact of Pesticides - Academy Publish

eans, roasted coffee, instant or granulated coffee, all of the same producer. Thesamples were treated by LLE and OCP pesticides were determined by GC/ECD.They contained pesticide residue levels between 1.0 and 7.0 µg kg -1 ,where thelowest MRL of pesticides analyzed is 10 µg kg -1 for the pesticide endrin(ec.europa.eu/sanco_pesticides 2005).Of the pesticides analyzed, lindane was foundin all samples. HCH and aldrin (7.0 µg kg -1 ) were detected in samples of roastedcoffee beans. Heptachlor was present in green coffee beans. DDT and itsmetabolites were not detected, probably because the green coffee beans, rich innutrients, promote the growth of microorganisms capable of degrading DDT and itsmetabolites(Stanciu, Dobrinas et al. 2008).Some studies show that spraying of pesticides on the coffee crop causecontamination of surface water, drinking water and agricultural soils. Europeanlegislation (ec.europa.eu/environment/water 1998) requires that pesticideconcentration levels in surface water is up to 1.0 µg L -1 and in drinking water 0.1 µgL -1 .López-Blanco et al. (2002 and 2003) studied different analytical methods fordetection of endosulfan in water samples collected near coffee plantations. Thispesticide is persistent in soil and can be transported towater through the flow ofparticles, usually determined as a mixture of isomers α- and β-endosulfan. Theauthors reported different extraction techniques, SPE, SPME and SDME, for theanalysis of α-and β-endosulfan in samples of surface water and drinking water byGC/ECD. Conditions were optimized for analysis of each extraction method,followed by comparative determination of some parameters of merit.The SPEmethod used a C 18 cartridge and hexane as solvent; the SPME method was selectedwith direct immersion of the fiber of divinylbenzene-Carboxenpolydimethylsiloxane(DVB/CAR/PDMS); and SDME method using isooctane asorganic solvent. The results showed that the SPE method requires significantlylonger analysis time (25 min) than necessary for SDME (20min) and SPME (15min). Moreover, SPE requires a high organic solvent volume (50 mL). However,SDME and SPME showed much lower recoveries (10% and 0.1%, respectively)than SPE (100%). The precision and reproducibility (RSD%) were very similar forboth isomers, being less than 14.4% regardless of the extraction technique used. Allthree methods showed good linearity (R 2 >0.995). The three pre-concentrationmethods showed low limits of detection compared with those established byEuropean legislation. However, the SDME technique was most sensitive. Effects ofthe matrix did not impair correct quantification of the SDME, SPE and SPMEmethods. Therefore, the three analytical methods were compared, where in terms ofcost the SDME method is most favorable because the cost of organic solvent isinsignificant compared to the cost of the SPE cartridge and SPME fiber (López-Blanco, Reboreda-Rodr guez et al. 2002; López-Blanco, Blanco-Cid et al. 2003).Lacorte, Vreuls et al. (1998) reported a program called SAMOS (System for theAutomated Monitoring of Organic pollutants in Surface water) to determinepesticide residues in rivers. The system was programmed so that eight samples wereanalyzed every day and could be operated for at least five days. These authorsanalyzed a mixture of triazines and other OPP. The samples were extracted by SPEmethod with a C 18 column and analyzed by HPLC/UV. The method showed goodlinearity (R=0.99) in the range of 0.3-1.5 ng L -1 and LOD ranging from 30 to 100 ngL -1 .The authors reported that Terbuthylazine, a herbicide used in coffee plantations,was detected at the concentration of 31 µg L -1 in the Llobregat Riverin Catalonia,Spain. This analysis was also performed by liquid chromatography with chemicalionization at atmospheric pressure coupled to mass spectrometry (LC-APCI/MS)and found the same results using this technique (Lacorte, Vreuls et al. 1998).AcademyPublish.org - The Impact of Pesticides385