Snake fruit or known as Salak is one of the favourite fruits and is consumed not only in Indonesia but also in the worldwide. The fruit may be contaminated with heavy toxic metals like cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), and lead (Pb). As a consequence, the validated methods for determination of these heavy metals are continuously developed. Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES) for determination of Cd, Cr, Cu, Ni, and Pb in snake fruit has been validated. The developed method was linear over the concentration range of 0.025 1.0 µg/mL for Cd, Cr, and Ni and 0.050 1.0 µg/mL for Cu and Pb, respectively. The values of coefficient of determination (r2) obtained for these regressions were higher than 0.99. The values of limit of detection (LoD) of Cd, Cr, Cu, Ni, and Pb found were at 0.0010 µg/mL, 0.0024 µg/mL, 0.0047 µg/mL, 0.0037 µg/mL, and 0.0091 µg/mL respectively, while limits of quantitation were of 0.0030 µg/mL (Cd), 0.0073 µg/mL (Cr), 0.0143 µg/mL (Cu), 0.0113 µg/mL (Ni), and 0.0274 µg/mL (Pb), respectively. The validated method was accurate and precise enough for determination of these heavy metals in snake fruit samples as indicated by acceptable values of recovery and low relative standard deviation (RSD) values. The developed method has been successfully used for determination of Cd, Cr, Cu, Ni, and Pb levels commercially available in the markets and farms.
Key words: method validation, snake fruit, ICP-AES, heavy metals
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