A solid-phase microextraction method for the chromatographic determination of organophosphorus pesticides in fish, water, potatoes, guava and coffee

Abstract

Este trabalho descreve um método de Microextração em Fase Sólida (SPME-CG) para a determinação de pesticidas organofosforados em amostras de peixes de água doce, água e outros alimentos por cromatografia em fase gasosa com detector de nitrogênio e fósforo. As amostras foram coletadas entre outubro de 2002 e abril de 2003 nos afluentes e subafluentes do rio Paranaíba que abastecem a cidade de Patos de Minas, Minas Gerais, Brasil. A determinação dos pesticidas coral (O,O-dietil-O-(3-cloro-4metil-2-oxo-2H-1-benzopiran-7-il) fosforotioato)), DDVP (2,2-dicloroetenil dimetilfosfato), di-siston (O,O-dietil S-[2-(etiltio) etil] fosforoditioato), etion (O,O,O',O'-tetraetil S,S'-metilenobisfosforoditioato), forato (O,O-dietil-S-etiltiometilfosforoditioato), fosdrin (O,O-dimetil-1-carbometoxi-1-propen-2-ilfosfato), gution (O,O-dimetil-S-(4-oxo-1,2,3-benzotrizina-3-metil) fosforoditioato)), malationa (O,Odimetil-S-(etil-1,2-dicarboetoxi) fosforoditioato) e parationa metílica (O-dimetil-O-4-nitrofenilfosforotioato) em amostras de peixes, água e outros alimentos, com o procedimento de SPME-CG utilizando uma microfibra de PDMS de 100 μm, é simples, fácil manuseio, econômica e livre de solvente. As condições otimizadas para a extração dos pesticidas com o método SPME-CG foram: amostras sob agitação, absorção à temperatura ambiente durante 40 min, dessorção a 220°C durante 10 min e volume de amostra no frasco de 16,0 mL. Utilizando-se estas condições foram obtidas curvas analíticas lineares em diferentes faixas de concentração (dependendo de cada pesticida) com coeficientes de correlação entre 0,997 a 0,999. A precisão estava adequada com desvios padrão relativos variando de 4,40 a 15,13%. O limite de detecção variou de 0,05 μg L-1 a 8,37 μg L-1 e o limite de quantificação de 0,09 μg L-1 a 8,70 μg L-1. O método foi empregado para detectar e quantificar pesticidas em 24 amostras de peixes de três espécies diferentes e também em água, batatas, goiaba e café. As amostras analisadas mostraram resíduos de seis pesticidas organofosforados diferentes. This paper describes a Solid Phase Microextraction method (SPME-CG) to the determination of organophosphorus pesticides in samples of freshwater fish, water, potatoes, guava and coffee by capillary gas chromatography with nitrogen phosphorus detector. The samples were collected from October 2002 to April 2003 in the tributaries and sub-tributaries of the Paranaiba River, which supplies the city of Patos de Minas, Minas Gerais, Brazil. The determination of the pesticides: coral (O,O-diethyl O-(3-chloro-4methyl-2-oxo-2H-1-benzopyran-7-yl) phosphorothioate), DDVP (2,2-dichloroethenyl dimethylphosphate), disyston (O,O-diethyl S-[2-(ethylthio) ethyl] phosphorodithioate), ethion (O,O,O',O'tetraethyl S,S'-methylene bis(phosphorodithioate)), phorate (O,O-diethyl S-ethylthiomethyl phosphorodithioate), phosdrin (2-methoxycarbonyl-1-methylvinyl dimethyl phosphate), guthion (O,Odimethyl-S-[(4-oxo-1,2,3-benzotriazin-3(4H)-yl)methyl] phosphorodithioate)), malathion (diethyl (dimethoxy thiophosphorylthio...

Degradation of Prototype Pesticides Submitted to Conventional Water Treatment Conditions: The Influence of Major Parameters

“…A 100-µm polydimethylsiloxane fiber (Supelco, Bellefonte, PA, USA) was selected for the present study as consistent results were obtained from our laboratory in previous works (Silva et al 1999;Capobiango and Cardeal 2005;Cardeal and Paes 2006). The fiber was directly immersed into the aqueous solutions (15 mL, placed in 20-mL flasks tightly closed with Teflon stopcocks) for 30 min at 40°C under magnetic stirring.…”

Recent achievements and applications of solid – phase microextraction in pesticide residues analysis in food

“…As the fiber coating is in direct contact with the sample phase, it has high extraction efficiency, and it is suitable for semivolatile compounds (Yang et al, 2013). Many types of pesticides have been determined in food matrices using the DI-SPME method such as organochlorine (Moliner-Martinez et al, 2010), OPPs (Capobiango et al, 2005;Saraji et al, 2013), carbamates (Song et al, 2013), triazoles (Souza-Silva et al, 2008), triazines (Djozan et al, 2008;Tian et al, 2014) and strobulines (Viñas et al, 2009). Alternatively to DI, in headspace-SPME (HS-SPME) mode, the extraction phase is placed in the headspace above the sample rather than immersed into the sample.…”

Sorptive extraction techniques in sample preparation for organophosphorus pesticides in complex matrices

“…SPME technology can be performed in two ways: (1) direct immersion of the fiber into the aqueous sample to extract analytes dispersed in aqueous solution; (2) exposure of the fiber in the sample headspace to extract volatile targets that are partitioned between gaseous and liquid phases [54]. SPME has been applied to OPPs analysis in various matrices with high efficiency and good reproducibility [55][56][57][58][59][60][61][62][63][64][65][66][67][68][69][70][71].…”