Investigation of organophosphate content on pear after washing treatment using HPLC / Muhammad Firdaus Abd Wahab

The importance of antioxidant in daily life has gained interest among consumer and scientific community in Malaysia. But the pesticide residue in fruit will give adverse effect to consumer and the pear are also included in the list of top 12 of the contaminated fruit. In this research, the objective was to carried out qualitative analysis of chlorpyrifos in organic pear and to determine the amount of chlorpyrifos content in pear using High Performance Liquid Chromatography (HPLC). Besides that, the effectiveness of the washing solution in removing chlorpyrifos content in pear was also investigated. The simple analytical method using Solid Liquid Extraction (SLE) was employed to extract the pear. A Reverse Phase High Performance Liquid Chromatography with C18 column as stationery phase was used for the separation process and 70:30 mobile phase compostion of acetonitrile and water was used as mobile phase. The system was carried out at the wavelength of 230 nm with ultraviolet detector and the flow rate at 1 mL/min. The successful extraction of chlorpyrifos using solid liquid extraction and the amount of the chlorpyrifos in the sample 1,2,3,4,5 and 6 were 9.7,3.2,4.6, 7.2, 7.0 and 1.8 ppm. The percent removal of chlorpyrifos using acetic acid, sodium chloride and tap water were 67%, 53 % and 26 % respectively. As a conclusion, the most effective washing solution was 10 % acetic acid and least effective was tap water. The simple extraction method using Solid Liquid Extraction was successful and the chlopyrifos was found in the organic pear.