EVALUATION OF THE SENSITIVITY AND SELECTIVITY OF A CHROME AZUROL S-IMMOBILIZED SORBENT FOR THE SORPTION-SPECTROPHOTOMETRIC DETERMINATION OF Cr(III) IONS

The selective determination of Cr(III) ions at trace levels is essential for environmental monitoring, industrial quality control, and water quality assessment. In this study, the sensitivity and selectivity of a Chrome Azurol S (CAS)-immobilized sorbent were evaluated for the sorption-spectrophotometric determination of Cr(III) ions. The sorbent was prepared by immobilizing Chrome Azurol S onto a silica gel matrix, providing a stable and highly active surface for the adsorption and detection of Cr(III). The effects of experimental variables, including solution pH, contact time, sorbent dosage, and initial metal ion concentration, were systematically optimized. Under the optimum conditions, the developed sorbent exhibited high adsorption efficiency, excellent sensitivity, and remarkable selectivity toward Cr(III) ions, even in the presence of common interfering metal ions. The proposed method demonstrated satisfactory linearity, precision, and reproducibility, confirming its reliability for trace analysis. The results indicate that the CAS-immobilized sorbent provides a simple, rapid, cost-effective, and environmentally friendly analytical approach for the sorption-spectrophotometric determination of Cr(III) ions in environmental water samples.