Utilize este identificador para referenciar este registo: http://hdl.handle.net/10400.18/504
Título: Optimisation of a solid-phase microextraction/HPLC/Diode Array method for multiple pesticide screening in lettuce
Autor: Melo, A.
Aguiar, A.
Mansilha, C.
Pinho, O.
Ferreira, I.
Palavras-chave: Pesticides
Quantitative Methods
Response Surface Methodology
Água e Solo
Data: 15-Fev-2012
Editora: Elsevier
Citação: Food Chemistry 2012;130:1090-1097
Resumo: A new method was developed for the determination of 10 pesticides widely used in lettuce production (acetamiprid, azoxystrobin, cyprodinil, fenhexamid, fludioxonil, folpet, iprodione, metalaxyl, pirimicarb, and tolyfluanid) using solid-phase microextraction (SPME) and liquid chromatography (HPLC) with diode-array detection (DAD). The extraction performance of four different SPME coatings, polydimethylsiloxane (PDMS), PDMS/divinylbenzene (PDMS/DVB), carbowax/templated resin (CW/TPR), and polyacrylate (PA) was evaluated using an interface SPME–HPLC. CW/TPR fibre was selected as the most appropriate for the extraction of majority of these pesticides. Three variables (pH, NaCl% and extraction time) were considered key factors in the optimisation process. Interactions between these analytical factors and their optimal levels were investigated by response surface methodology based on central composite design. The method allowed the determination of azoxystrobin, cyprodinil, fenehexamid, fludioxonil, folpet, iprodione, and tolyfluanid in lettuce at concentrations between 0.8 and 25.6 mg/kg, i.e., bellow the maximum residues levels allowed for those compounds in lettuce. Lettuce samples that suffered pesticide treatments with folpet and fenehexamid were analysed during days to harvest to study the dissipation behaviour of the pesticides used. Concentration of folpet was 92.8; 53.4; 22.9; 17.9; 7.45; 1.85 mg/kg and concentration of fenhexamid was 158.1; 76.2; 31.0; 27.3; 7.24; 0.87 mg/kg, respectively for t0, t1, t3, t6, t7, t9 days, and not detected at t14 days for the two pesticides.
Peer review: yes
URI: http://hdl.handle.net/10400.18/504
ISSN: 0308-8146
Versão do Editor: www.sciencedirect.com/science/article/pii/S0308814611011150
Aparece nas colecções:DSA - Artigos em revistas internacionais

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