ABSTRACT
TLC has been used in combination with micro-extraction and clean-up methods to
provide an alternative cost effective analytical procedure for screening pesticide
residues in plant matrices. Thirty-five (35) agrochemicals, which are used in priority
crops in Ghana, were used in this study.
Ethylacetate extraction in the presence of anhydrous sodium sulphate, followed by gel
permeation chromatographic clean up and additional purification on silica gel
cartridges provided clean extracts enabling the application of 300mg sample
equivalent on the TLC plates.
Detection method involving the use of O-tolidine was found to be suitable for general
screening of residues, having medium sensitivity for several compounds. The method
involving the use of silver nitrate was the only one found to be most suitable for
detecting the organochlorine pesticides. Lindane was the most sensitive to this
reagent and had a Minimum Detectable Quantity (MDQ) value of 5ng/5 uL. This
method was suitable for use on only alumina plates and detection was also possible
even under sunlight.
The enzyme inhibition methods were very sensitive to the carbamate and phosphoric
acid type insecticides with MDQ values between 0.2 and 2000ng.
Other detection methods involving p-nitrobenzene, p-dimethylaminobenzaldehyde
and photosynthesis inhibition were also tried and discussed.
The database developed has been successfully used for screening and semiquantitative
determination of some ranges of pesticide residue in soil and plant
matrices.
LOWOR, S (2021). DEVELOPMENT OF METHODS FOR SCREENING PESTICIDE RESIDUES IN PLANT MATRICES IN GHANA. Afribary. Retrieved from https://afribary.com/works/development-of-methods-for-screening-pesticide-residues-in-plant-matrices-in-ghana
LOWOR, SAMUEL "DEVELOPMENT OF METHODS FOR SCREENING PESTICIDE RESIDUES IN PLANT MATRICES IN GHANA" Afribary. Afribary, 31 Mar. 2021, https://afribary.com/works/development-of-methods-for-screening-pesticide-residues-in-plant-matrices-in-ghana. Accessed 10 Dec. 2024.
LOWOR, SAMUEL . "DEVELOPMENT OF METHODS FOR SCREENING PESTICIDE RESIDUES IN PLANT MATRICES IN GHANA". Afribary, Afribary, 31 Mar. 2021. Web. 10 Dec. 2024. < https://afribary.com/works/development-of-methods-for-screening-pesticide-residues-in-plant-matrices-in-ghana >.
LOWOR, SAMUEL . "DEVELOPMENT OF METHODS FOR SCREENING PESTICIDE RESIDUES IN PLANT MATRICES IN GHANA" Afribary (2021). Accessed December 10, 2024. https://afribary.com/works/development-of-methods-for-screening-pesticide-residues-in-plant-matrices-in-ghana