title: Optimization of QuEChERS method for the analysis of organochlorine pesticides in soils with diverse organic matter.
abstract: A QuEChERS method has been developed for the determination of 14 organochlorine pesticides in 14 soils from different Portuguese regions with wide range composition. The extracts were analysed by GC-ECD (where GC-ECD is gas chromatography-electron-capture detector) and confirmed by GC-MS/MS (where MS/MS is tandem mass spectrometry). The organic matter content is a key factor in the process efficiency. An optimization was carried out according to soils organic carbon level, divided in two groups: HS (organic carbon >2.3%) and LS (organic carbon <2.3%). The method was validated through linearity, recovery, precision and accuracy studies. The quantification was carried out using a matrix-matched calibration to minimize the existence of the matrix effect. Acceptable recoveries were obtained (70-120%) with a relative standard deviation of ≤16% for the three levels of contamination. The ranges of the limits of detection and of the limits of quantification in soils HS were from 3.42 to 23.77 μg kg(-1) and from 11.41 to 79.23 μg kg(-1), respectively. For LS soils, the limits of detection ranged from 6.11 to 14.78 μg kg(-1) and the limits of quantification from 20.37 to 49.27 μg kg(-1) . In the 14 collected soil samples only one showed a residue of dieldrin (45.36 μg kg(-1) ) above the limit of quantification. This methodology combines the advantages of QuEChERS, GC-ECD detection and GC-MS/MS confirmation producing a very rapid, sensitive and reliable procedure which can be applied in routine analytical laboratories.
authors: REQUIMTE, Instituto Superior de Engenharia do Porto, Porto, Portugal.
authors: Luísa
authors: L
authors: Correia-Sá
authors: Virgínia C
authors: VC
authors: Fernandes
authors: Manuela
authors: M
authors: Carvalho
authors: Conceição
authors: C
authors: Calhau
authors: Valentina F
authors: VF
authors: Domingues
authors: Cristina
authors: C
authors: Delerue-Matos
mesh_terms: D002849:Chromatography, Gas; D008401:Gas Chromatography-Mass Spectrometry; D006843:Hydrocarbons, Chlorinated / Q000737:chemistry / Q000302:isolation & purification*; D057230:Limit of Detection; D010575:Pesticides / Q000737:chemistry / Q000302:isolation & purification*; D012989:Soil Pollutants / Q000737:chemistry / Q000302:isolation & purification*; D052616:Solid Phase Extraction / Q000379:methods*
chemical_list: D006843:Hydrocarbons, Chlorinated; D010575:Pesticides; D012989:Soil Pollutants