Extraction with edta/methanol and supercritical carbon dioxide for the analysis of ziram residues on spinach

Two different analysis procedures for Ziram residues on spinach are described. One consists in the extraction of 1 g of lyophilized sample with a 1:1 (v/v) aqueous EDTA‐methanol solution and later partition with hexane as clean‐up. The other procedure involves supercritical carbon dioxide, with the addition of methanol as an organic modifier, to perform the extraction of 0.25 g of lyophilized sample. In both cases, the determination is performed by High Performance Liquid Chromatography and ultraviolet detection. A discussion of both procedures is presented, applying them to the study of the dissipation of Ziram on spinach cultivated in greenhouses at two different environmental temperatures.

Key words:

• Ziram residues analysis
• spinach
• kinetics

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