Determination of Arsenic in Palm Kernel Expeller using Microwave Digestion and Graphite Furnace Atomic Absorption Spectrometry Method

A study on the method to determine arsenic in palm kernel expeller wascarried out. Microwave digestion technique is widely applied in the analytical chemistry field. In comparison to conventional sample digestion method, the microwave technique is simple, reduced contamination, usage of safe reagent and matrix completely digested. A graphite furnace atomic absorption spectrometry method was used for the total determination of arsenic in palm kernel expeller. Arsenic was extracted from palm kernel expeller in a closed vessel digestion system with nitric acid and hydrogen peroxide. The results showed that the optimal ashing and atomizing temperatures were 800°C and 2400°C respectively. The limit of detection was estimated to be 0.001 ppm. The mean recoveries of arsenic for repeatability and reproducibility for 1, 2 and 4 ppm were in the range between 79 –90%. Ten samples of palm kernel expeller from mills were analyzed to contain 0.18 to 3.05 ppm of arsenic. Therefore, is proposed that this method be used to detect arsenic in palm kernel expeller.