Behavior Of Pesticide Residues Extracted From Different Cotton Fibers Determined By The Interaction With Green Algae

The study is focused on the monitoring of changes in the oxygen level caused by the interaction of residual analytes and the green algae, Scenedesmus (chlorophyta), for the detection of pesticides and hazardous compounds. The advantages of being photoautotroph, morphologically simple and having relatively simple reproductive system makes algae a suitable criterion for the determination of intervening predators affecting their normal life cycle. Algae Growth Analyzer equipped with miniature sensitive oxygen electrode, a light source and cover to model light and dark phases was used enabling to follow the lifecycle of algae producing oxygen. The device was controlled by Bioanalyzer Potentiostat for the evaluation of oxygen electrode response. Three different varities of cotton namely Giza 86 from Egypt, MNH 93 from Pakistan and cotton from India of the crop 2010/2011 were analyzed. One of each cotton samples was the classical conventional cotton and the other was organic cotton produced without utilizing the pesticides. Cryogenic homogenization was carried out for sample pretreatment and Ultrasound assisted extraction (USE) was used with the solvent, Acetonitrile, for each of the samples, respectively. The resulted extracts were filtered and then the solvent was evaporated completely in petri dishes at room temperature so as to ignore the impact of solvent in the communication of analytes with algae. Algae were added in the petri dishes and then allowed to cultivate for one hour with each sample, respectively. The cultivated algae were injected stepwise in the Algae Growth Analyzer. The method shows reasonable results and can successfully be utilized for the detection of residual pesticides on different types of cotton and especially to compare the classical conventional and organic cotton in terms of their cytotoxicity.