Análise multirresíduo de agrotóxicos em abacaxi por CG/DCE / Analysis multiresidue of pesticides in pineapple by GC/ECD

AUTOR(ES)
DATA DE PUBLICAÇÃO

2010

RESUMO

The objectives of this work were to optimize the technique of extraction by matrix solid-phase dispersion (MSPD) and the solid-liquid with partition in low temperature extraction technique (SLE-LTP), and to validate this latter, to the residues analysis of the pesticides atrazine, thiamethoxam, triadimenol and deltamethrin in pineapple samples, by gas chromatography with electron capture detector (GC/ECD). In the optimization stage of the extraction technique solid-liquid with partition in low temperature, factors that influence in the percentage of recovery of pesticides, and provide ideal conditions of analysis, were evaluated. The optimized method was validated thorugh the determination of the selectivity, the linearity of answer of the method, the limit detection, the limit quantification, the accuracy and the precision. The obtained results showed that the technique SLE-LTP is efficient for analysis of the pesticides thiamethoxam, triadimenol and deltamethrin, with superior recovery percentages up to 90%, and atrazina, with percentage of recovery of approximately 60%. Besides, the quantification limits for the thiamethoxam, triadimenol and deltamethrin (0,050; 0,17 e 0,040 μg g-1) were smaller than the allowed maximum limits of residues (LMR), established for these pesticides in pineapple, by the European Union. The optimized and validated technique was applied to samples of pineapple, Pérola cultivar, from the cities Marataízes (ES), Miracema do Tocantins (TO) e Monte Alegre de Minas (MG), not being detected the presence of residues of the pesticides studied in the pineapple samples analyzed. It was also studied, the influence of the components of the pineapple in the quantification of the pesticides in analyses for chromatography in gaseous phase, using the matrix method overlap. The results showed that the co-extractives of the matrix affect significantly in the quantification of the pesticides in study. With the intention of comparing the technique SLE-LTP, the technique of extraction matrix solid-phase dispersion was optimized, being appraised the adsorbent, the eluent, and later accomplished a planning factorial 23 to evaluate the simultaneous behavior of the factors: (1) proportion between adsorbent and sample, (2) co-column use and (3) ultrasound use. The cocolumn presence, besides influencing in the percentage of recovery of the pesticides atrazine, thiamethoxam and triadimenol, affects qualitatively the chromatogram. Comparing the extraction techniques SLE-LTP and MSPD, both present high recovery levels for the pesticides in study, except for the atrazine, in that SLE-LTP presented recovery percentages higher. Besides, the extracts obtained in SLE-LTP are less susceptible to the presence of interferences.

ASSUNTO(S)

partição em baixa temperatura abacaxi análise de multirresíduos quimica analitica analysis multiresidue pineapple partition in low temperature

ACESSO AO ARTIGO

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