Determinação de residuos de herbicidas em aguas utilizando extração em fase solida seguida de separaçaõ por cromatografia liquida e alta eficiencia

AUTOR(ES)
DATA DE PUBLICAÇÃO

1999

RESUMO

The success of agricultural production depends on the application of chemical substances, pesticides, that control the pests. If on the one hand, the application of pesticides is indispensable, on the other hand, it can very be dangerous for the environment and to human health. The pesticides can be carried to sources of water, causing contamination. Worldwide, concern with the quality of water has grown and, thus, the development of methods to analyze these contaminants in the environment becomes necessary. In the present work, a fast, simple and efficient method was developed to separate, identify and quantify nine herbicides present in water samples. They are: bentazon; 2,4D; cyanazine; simazine; fluazifop acid; atrazine, diuron, linuron and ametrin. The method consists of high performance liquid chromatography (HPLC) with reversed phase, using, as stationary phase Nova-Pak C-18, and as mobile phase, MeOH:H2O 60:40, v/v, pH=4,6 (adjusted with phosphoric acid), with UV detention at 230 nm. To obtain the allowed limits, that is 0.1 mg/L of each pesticides, an extraction and pre-concentration step of these herbicides was made, using solid phase extraction (SPE) with C-18 tubes. After the development of the method, it was validated using the parameters: precision (repeatability) and accuracy, calibration, linearity, recovery and sensitivity (detection and quantification limits). Precision and accuracy were less than 15%, the linearity were good for all herbicidas (r >0.999), the recoveries were between 63.1 and 97.8% and the average detection limits were approximately 21.4 ng/L, except for fluazifop acid (12.0 mg/L), thus reaching the low limits established by international organizations.

ASSUNTO(S)

validação de metodo pesticidas

ACESSO AO ARTIGO

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