Relative Abundance Of Pesticides in Fruits and Vegetables by GC/MS

GC/MS is a technique used for the identification of pesticide residues in a given sample. The extraction of pesticides from the sample is done by using a solvent. The GC/MS gives the elution, retention time and molecular weight of each pesticide in the residue. The data obtained is then compared with that of a referenced pesticide. In this experiment spinach, guava and orange were used. The samples were divided into two groups: - fruits/vegetables with pesticides and fruits/vegetables without pesticides. The samples were extracted with acetonitrile in a mixture of toluene. The extract was then analyzed in GC/MS. The elution and retention time of pesticides residue was calculated and the molecular weight of each pesticide was determined. The results showed that low molecular weight pesticides were eluted first and then the high molecular weight pesticides were eluted. The molecular weight of each pesticide residue was compared with the reference data and the pesticides were identified and the relative abundance of each pesticide was calculated from GC/MS spectrum.