Organophospiorus Pesticides Residues in Soil for Microwave- Assisted Extraction

• Main Authors: Lin, Yu-ju, 林玉茹
• Other Authors: Ho, Wu-hsiung
• Format: Others
• Language: zh-TW
• Published: 1996
• Online Access: http://ndltd.ncl.edu.tw/handle/25056349102453595096

碩士 === 國立中興大學 === 化學系 === 84 === This study has been investigated for the practicability of residues analysis of organophosphorus pesticides in soil using microwave-assisted extraction. The effect of microwave-assisted extraction was emphasized in the study. Finally, GC/P-FPD method for qualitative and quantitative determination was adopted. First of all the possible factors for the decomposition of organophosphorus pesticides with microwave were considered without the existence of matrix. The factors were the kind of solvent, power of microwave and the heating time etc. The results were shown that the effects were not obvious for solvent types. When the power of microwave was too high and the heating time too long, the recovery of organophosphorus pesticides were lowered. The investigations of real sample were proceeded in similar way. The best condition from the results were 20mL n- hexane/ethyl acetate (v/v,1+1) for extraction solvent, the power of microwave 75% and the heating time 5 minutes. Real samples were extracted by microwave-assisted extraction, then the extract was filtered and concentrated and then injected in GC. The effect for the existence of water was considered, the recovery of 5 organophosphorus pesticides were lowered. The setting effect for organophosphorus pesticides was observed. In 10 days, organophosphorus pesticides had already been decomposed. sphorus pesticides could be determined with GC/P-FPD in 16 minutes. The linear relative coefficients for calibration curve of real sample were higher than 0.99. Besides of the recovery of dichlorvos (31.9~68.0%), the recovery of other 4 organophosphorus pesticides were 87.5~127%, and limits of detection were 35.32~109.1ppb.