Title: IMPROVEMENT OF PURIFICATION METHOD FOR DIAZINON FROM SOIL MATRIX
Authors: Masud Hassan, Rakib Hassan, SamiaHaque, Zakia Sultana and Marufa Aktar
Abstract: Diazinon is common pesticides used in the highest amount for paddy production in Bangladesh. In this study, we applied diazinon in different experimental agricultural fields of paddy. The present work was aimed to develop a clean-up method for diazinon from soil matrix. The work also included to the mass of soil extracted (1/5 of the reported) which proportionally will reduce chemicals and solvents used in the reported method. The analysis carried out by GC-ECD, purity of standard diazinon was 97.5%. Solvents and sample blank were injected before analysis of cleaned extracts. For clean-up silica gel and florisil were used; cleaned extract obtained from silica gel column was found to contain less impurity than the cleaned extract of florisil column. Percent recovery of the two columns was found to be 92.70 +_ 1.25 and 88.33 +_1.36, respectively. The best eluting solvent for silica gel column was dichloromethane-methanol mixture (95:5). A few more experiments are necessary to validate the clean-up process. Therefore, for real soil sample extraction will be done taking 10g soil instead of 50g. Silica gel column will be used for clean-up instead of florisil which is cheaper and easily available.