Simultaneous determination of parathion and p-nitrophenol in vegetable tissues by derivative spectrophotometry.
A first derivative spectrophotometric method has been developed for the determination of parathion and p-nitrophenol in vegetable tissues. Ethanol was used as solvent for extracting the compounds from the tissues and subsequently the samples were evaluated against a vegetable tissue blank, directly by derivative spectrophotometry. The simultaneous determination of these compounds can be carried out using the zero-crossing approach for parathion at 253.0 nm and for p-nitrophenol at 273.1 nm. In the samples each analyte was determined in the presence of one another in the ranges between 4.9 to 3883.5 microg g(-1) for parathion and 4.9 to 3285.3 microg g(-1) for p-nitrophenol. The detection limits (3a) were found to be 1.5 and 1.4 microg g(-1) for parathion and p-nitrophenol, respectively. The relative standard deviations were in all instances less than 1.8%. The proposed method was applied to the determination of the analytes in spiked leaves of corn. The results show a good recovery and they are in agreement with those obtained by polarography.
Department of Chemistry, Faculty of Sciences, University of Chile, Santiago. analitic@abello.dic.uchile.cl
M Inés
MI
Toral
Alejandra
A
Beattie
Claudia
C
Santibañez
Pablo
P
Richter
D002138:Calibration; D007306:Insecticides / Q000032:analysis*; D009596:Nitrophenols / Q000032:analysis*; D010278:Parathion / Q000032:analysis*; D010573:Pesticide Residues / Q000032:analysis*; D012680:Sensitivity and Specificity; D012997:Solvents; D013053:Spectrophotometry / Q000379:methods; D014675:Vegetables / Q000737:chemistry*
D007306:Insecticides; D009596:Nitrophenols; D010573:Pesticide Residues; D012997:Solvents; D010278:Parathion; C024836:4-nitrophenol