VALIDASI METODE ANALISIS Fe DALAM LARUTAN NON-CRM MELALUI DESTRUKSI H₂SO₄ DAN SPEKTROFOTOMETRI UV-VIS

Abstract

Quantitative determination of iron (Fe) is essential due to its significant impact on both biological systems and the environment. This study validated a UV-Vis spectrophotometric method for Fe analysis using H₂SO₄ digestion and complexation with KSCN, employing a non-certified FeCl₃ standard solution (non-CRM). The aim was to evaluate the feasibility of this method as an efficient and cost-effective alternative for laboratories lacking access to certified reference materials (CRM). The validation covered parameters including linearity, accuracy, precision, limit of detection (LoD), and limit of quantification (LoQ). The Fe-thiocyanate complex showed a maximum absorbance at 454 nm. A strong linear relationship between concentration and absorbance was observed, with a determination coefficient (R²) greater than 0.99. Accuracy testing yielded recovery values within the acceptable range of 90-110%, indicating high measurement reliability. Interday precision involving three analysts produced relative percent differences (RPD) below 2%, reflecting good repeatability. The obtained LoD and LoQ values were sufficiently low, confirming the method’s high sensitivity. Based on these results, the validated UV-Vis spectrophotometric method can serve as a reliable and practical alternative for Fe analysis, particularly in laboratories with limited access to certified standards.