VALIDATION OF LEAD (Pb) ANALYSIS METHOD IN FISH MEAL MATRIX BY ELECTROTHERMAL ATOMIC ABSORPTION SPECTROPHOTOMETRY

Validation of analytical methods is the process of proving that the methods used are scientifically good and suitable for certain purposes. The aim of this study was to validate the analytical method of lead in fish meal matrix by electrothermal atomic absorption spectroscopy (ETAAS) using a phosphate modifier. The research begins with optimization of the analytical conditions that include pyrolysis (ashing) and atomizing temperature, and continues with the validation process by evaluating the analytical performance parameters using a certified reference material (CRM). Method validation was carried out by determining the level of accuracy and precision as well as lead content in a CRM Cod Muscle-422 from BCR. Each experiment was conducted at a wavelength of 283.3 nm, a lamp current of 9.0 amperes, a slit width of 1.3 nm and an argon carrier gas. The optimal pyrolysis and atomizing temperature of lead obtained by adding phosphate modifier was 650 oC and 2000 oC, respectively. The results obtained in this study indicate that the ETAAS lead analysis method using a phosphate modifier is feasible as a test method with an RSD of 3.79%, precision of 0.0043, relative error of 4.0%, accuracy of 104% and recovery of 98% ± 3%. The results of the validation method obtained that the 95% confidence interval for Pb content was 0.088 ± 0.023 µg/g, still within the range of Pb levels in the certificate, namely 0.085 ± 0.015 µg/g of Pb.