Spectrophotometric Determination of Azinphos methyl Based on Aggregation of Colloidal Gold Nanoparticle

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Bakht Khosh Hagh, Haleh | 2014

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Type of Document: M.Sc. Thesis
Language: Farsi
Document No: 46420 (03)
University: Sharif University of Technology
Department: Chemistry Science
Advisor(s): Hormozi-Nezhad, Mohammad Reza; Torkian, Ayoub
Abstract:
There is an increasing need for food by the growth of population. To meet this need, the use of pesticides is increasing. Among pesticides organophosphorous compounds are the ones with the most usage. Liquid and gas chromatography are commonly used to measure orghanpphosphrous pesticides. These methods are relatively time consuming and require a tedious sample preparation.
Herein we report a sensitive colorimetric method for detection and measurement of Azinphos methyl, based on unmodified gold nanoparticles aggregation and changes in plasmonic band. Azinphos methyl, containing different soft acidic groups acts as a bridge, causes aggregation, and changes in plasmonic band. Changes in plasmonic band include absorbance intensity decrease at 520 nm and intensity increase at about 650 nm. Two calibration curves derived from the ratio of absorbance at 660 nm and 640 nm to absorbance at 520 nm respectively with 3 and 1 nM of Au-NPs. Linear range of first one is 0.05-0.5 ppm and for second one is 0.75-3 ppm. Detection limits are 0.0875 and 0.0657 ppm respectively
Keywords:
Colorimetric ; Gold Nanoparticle ; Spectrophotometry ; Organophosphorus Pesticide ; Azinphos Methyl

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