Optimisation and validation of a solid-phase microextraction method for simultaneous determination of different types of pesticides in water by gas chromatography-mass spectrometry.

E Beceiro-González; E Concha-Graña; A Guimaraes; C Gonçalves; S Muniategui-Lorenzo; M F Alpendurada

doi:10.1016/j.chroma.2006.12.042

Home/Archive/PubMed

PubMed · 17204271

Optimisation and validation of a solid-phase microextraction method for simultaneous determination of different types of pesticides in water by gas chromatography-mass spectrometry.

E Beceiro-González·E Concha-Graña·A Guimaraes·C Gonçalves·S Muniategui-Lorenzo·M F Alpendurada

View original source ↗Export metadata ↓

Abstract

A solid-phase microextraction (SPME) method for the simultaneous determination of a large number of pesticides (46) with a wide range of polarities and chemical structures (organochlorine, organophosphorous, triazines, pyrethroids and others) in water samples by GC-MS has been developed. Three different fibres and parameters that influence the extraction and desorption efficiency were studied. The selected conditions were: a 60 microm polydimethylsiloxane/divinylbenzene (PDMS/DVB) fibre, 45 min of extraction time, sample agitation and temperature control at 60 degrees C; neither pH adjustment nor ionic strength correction were applied. Good detection limits, linearity and repeatability were obtained with this method for the 46 pesticides studied. The method was validated for 29 pesticides following the recommendations of the international norm ISO/IEC 17025 including the calculation of the uncertainties. The detection limits ranged from 4 to 17 ng l(-1). Furthermore, repeatability (6.9-20.5%) and intermediate precision (4.5-19.7%) were shown to be satisfactory. To validate matrix effects for drinking and surface water analytical recoveries were calculated for these matrices. The accuracy of the method was also evaluated by participating in a proficiency inter-laboratory test.

Explore related subjects

Gas Chromatography-Mass Spectrometry Pesticides Reproducibility of Results Sensitivity and Specificity Water Pollutants, Chemical Journal Article Research Support, Non-U.S. Gov't Validation Study

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

E Beceiro-González, E Concha-Graña, A Guimaraes, C Gonçalves, S Muniategui-Lorenzo, M F Alpendurada. 2006-12-17. Optimisation and validation of a solid-phase microextraction method for simultaneous determination of different types of pesticides in water by gas chromatography-mass spectrometry.. https://doi.org/10.1016/j.chroma.2006.12.042

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2007

Photochemistry in the mixed aqueous solution of nitrobenzene and nitrous acid as initiated by the 355 nm UV light.

The 355 nm photon-initiated microscopic reaction mechanisms of the mixed aqueous solution of nitrobenzene and nitrous acid in the presence or absence of O(2) were studied by the laser flash photolysis technique. The main transient absorption peaks in the recorded spectra were assigned and the growth/decay trends of several transient species were investigated. It was found that the OH radical formed from the photolysis of nitrous acid triggered most of the subsequent radical reactions. The rate constant of the reaction between OH radical and nitrobenzene was measured to be (3.4 +/- 0.1) x 10(9) l mol(-1) s(-1). The product from this reaction, namely C(6)H(5)NO(2)-OH adduct, was found to react with O(2) to yield C(6)H(5)NO(2)-OHO(2) adduct with a rate constant of (1.6 +/- 0.2) x 10(9) l mol(-1) s(-1). Final steady-state products were identified by GC/MS analysis and were in accordance with the transient spectroscopic results. The possible reaction pathways were proposed.

Gas Chromatography-Mass Spectrometry↗

PubMed2007

Integrating profiling data: using linear correlation to reveal coregulation of transcript and metabolites.

Recent advances in the medical and biological sciences have been characterized by a major paradigm shift from reductionism to integrated and holistic systems approaches. Such approaches are characterized at the experimental level by the multiparallel analysis of a multitude of parameters of a given biological system at a range of different molecular levels, following the systematic perturbation of the system in question. Although a multitude of studies have been carried out to assess the transcript, protein, and metabolite complements of cells under various conditions, to date, few have been attempted that encompass the profiling of more than one of these entities. In this chapter, we describe combined analysis of data obtained from transcript and metabolic profiling, and detail advantages of using both approaches in parallel.

Gas Chromatography-Mass Spectrometry↗

PubMed2006

Optimization of a procedure for the selective isolation of some powerful aroma thiols. Development and validation of a quantitative method for their determination in wine.

This paper deals with the isolation properties of four relevant wine mercaptans in two different separation systems and with the subsequent development, optimization and validation of an analytical procedure for their quantitative determination. 4-Methyl-4-mercaptopentanone (4M4MP), 2-furanmethanethiol (FFT), 3-mercaptohexanol (3MH) and 3-mercaptohexyl acetate (AMH) can be quantitatively extracted from 200 ml of wine in a bed packed with 1 g of LiChrolut EN resins. Fatty acids and diverse interfering compounds are removed by rinsing with an aqueous solution with a 40% of methanol and buffered at pH 7.2 with alpha,alpha,alpha-tris-(hydroxymethyl)-aminomethane (TRIS) 0.2 M. Mercaptans can be further isolated by extraction with an aqueous solution of 1 mM p-hydroxymercury benzoate. Best results were achieved with an extraction with a solution at pH 10.7 with 0.2 M 4-(2-hydroxyethyl)piperazine-1-ethanesulfonic acid (HEPES), further acidification to pH 7.5, release of thiols by the addition of dithioerythritol and extraction with 2 x 0.75 ml dichloromethane. The extract is concentrated to 200 and 20 microl are finally injected in a gas chromatograph-ion trap mass spectrometric system. Method detection limits are 0.8, 6, 15 and 5 ng l(-1) for 4M4MP, FFT, MH and AMH, respectively. The recovery in the sample pre-treatment was 76, 45, 75 and 95%, respectively. Repeatability and linearity are also satisfactory. Different critical aspects, such as the effect of air or the evaporation of the extract were also studied.

Gas Chromatography-Mass Spectrometry↗