Application of solid-phase microextraction to the analysis of volatile organic compounds in water

Santos, F.J.; Galcerán, M.T.; Fraisse, D.

doi:10.1016/0021-9673(96)00231-2

Cited by 69 publications

(30 citation statements)

References 18 publications

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“…As has been reported, for quantitative analysis it is not necessary for the analytes to reach equilibrium as long as the extractions are carefully timed and the mixing conditions and volumes remain constant. 21 So, an adsorption time of 30 min has been selected for the extraction for both the PDMS and PA fibers to keep the total extraction time comparable with the chromatographic run time.…”

Section: Effect Of Extraction Time and Temperaturementioning

confidence: 99%

Optimization of Headspace Solid-Phase Microextraction for the Determination of Pesticide Residues in Vegetables and Fruits

2008

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Pesticides, including organochlorine pesticides (OCPs) and organophosphorous pesticides (OPPs) are examples of wellknown environmental contaminants. OPPs are used as a substitute for OCPs in many countries nowadays because they can degrade more easily in the environment. Although OPPs as a whole are not the most toxic pollutants, they can be traced to a wide range of surface water, fruits, vegetables and foodstuff. 1For fast monitoring of the environmental contamination caused by OCPs and OPPs and to accomplish risk assessment, more sensitive, rapid and simple analytical methods are paramount.Liquid-liquid extraction (LLE) and solid-phase extraction (SPE) are the most popular methods for extracting pesticides. However, they are time consuming and labor-intensive, and require large volumes of sample and solvents. In addition, because pesticides generally are present at ppt levels, mixed with other contaminants at higher concentrations, interfering compounds can produce extraneous peaks. LLE and SPE can carry contaminants into the final sample, producing a high background. 2-4Solid-phase microextraction (SPME), developed by Kataoka et al.,5 has received an increasing amount of attention at the analytical level in numerous scientific disciplines. 6 It is simple 6,7 and, as will be discussed later, offers great flexibility. In comparison with direct SPME, headspace (HP) SPME can shorten the time of extraction significantly because the diffusion rate of the analytes in gaseous phase is faster than that in the aqueous phase.1 Only a few references on the application of HS-SPME for the determination of OCPs and OPPs in fruit and vegetable samples can be found. 8,9 Most applications are based on the preparation of fruit or vegetable juices and analysis of target compounds by directly dipping of the SPME fibers into the slurry. [9][10][11][12][13][14] However several disadvantages related to fiber stability and sensitivity have been pointed out. Such problems can be overcome if headspace SPME is applied. Since the fiber is not in contact with the sample, background adsorption and matrix effects can be reduced, which also enhances the life expectancy of the SPME fibers. The objectives of this study are to evaluate the HS-SPME process by comparing two coating materials and to optimize the main parameters affecting the HS-SPME. Finally, we intended to develop an efficient multi-residue method on the basis of HS-SPME to extract each selected pesticide in fruit and vegetable samples. Experimental Chemicals and reagentsEight pesticides standards which are popular used by local farmers in vegetable and fruit cultivation 15 were > 95% pure and were purchased from AccuStandard Inc., USA. Stock solutions of each pesticide were prepared. Working standard solutions were prepared daily by volume dilution in distilled water. In the calibration and quantitation studies, an internal standard, 1-chloro-4-fluorobenzene, 200 mg/L which is effective as a surrogate to compensate the data of all 8 kinds of pesticides was added to each sample...

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Section: Effect Of Extraction Time and Temperaturementioning

confidence: 99%

Optimization of Headspace Solid-Phase Microextraction for the Determination of Pesticide Residues in Vegetables and Fruits

2008

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“…As soluções das amostras foram preparadas empregando os solventes etanol e água segundo SANTOS, GALCERAN & FRAISSE [18]. A concentração da solução intermediária obtida foi igual a 40µg/L de cúrcuma.…”

Section: -Preparo Das Soluções Das Amostrasunclassified

“…O estudo da otimização da partição e dessorção dos voláteis baseou-se nos procedimentos adotados por YANG & PEPPARD [23] e SANTOS, GALCERAN & FRAISSE [18]. Testes preliminares foram realizados a fim de verificar o tempo e a temperatura a serem empregados na partição e dessorção dos compostos volá-teis da cúrcuma.…”

Section: 32-estudo Das Condições De Partição E Dessorçãounclassified

“…A linearidade das respostas das soluções padrões na extração, empregando a técnica SPME, foi verificada e baseou-se no método descrito por SANTOS GALCERAN & FRAISSE [18]. Para este estudo, foram utilizadas as soluções de trabalho do pool dos padrões.…”

Section: -Estudo Da Linearidade Das Respostas Das Soluções Padrõesunclassified

“…Os coeficientes de variação (CV) observados para as diferentes concentrações dos padrões foram de 3 a 17%, podendo ser considerados aceitáveis. Também SANTOS, GALCERAN & FRAISSE [18] encontraram valores de R 2 na faixa de 0,9982 a 0,9996 e CV variando de 7 a 13% em seus estudos de otimização da técnica de SPME para análise de compostos orgânicos voláteis da água.…”

Section: -Emprego Dos Padrões De Borneol Limoneno E Linalolunclassified

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