A simple, precise, inexpensive and reproducible spectrophotometric method was investigated for the determination of chromium ion (III) in aqueous media, this method based on the formation of a complex between chromium...A simple, precise, inexpensive and reproducible spectrophotometric method was investigated for the determination of chromium ion (III) in aqueous media, this method based on the formation of a complex between chromium ion (III) and ninhydrin, a deep greenish-violet colored product in the presence of potassium hydroxide was obtained. The absorption of this product was measured at λ<sub>max</sub> = 375 nm. The reaction proceeds quantitatively at room temperature. The linear calibration curve was constructed over range of (4.8 × 10<sup>-4</sup> - 1.6 × 10<sup>-2</sup>) mol/L of chromium ions with molar absorptivity of 2.90 × 10<sup>2</sup> and correlation coefficient R<sup>2</sup> = 0.9989. The calculated Sandell’s sensitivity value is 0.179 μg/cm<sup>2</sup>, the limits of detection (LOD) and the limit of quantification (LOQ) are found to be 3.74 × 10<sup>-5</sup> and 1.24 × 10<sup>-4</sup> mol/L, respectively. The method was successfully applied for determination of the chromium ion in aqueous solution. The stoichiometry of the reactions was determined molar combining ratio of 1:2 between chromium and ninhydrin.展开更多
文摘A simple, precise, inexpensive and reproducible spectrophotometric method was investigated for the determination of chromium ion (III) in aqueous media, this method based on the formation of a complex between chromium ion (III) and ninhydrin, a deep greenish-violet colored product in the presence of potassium hydroxide was obtained. The absorption of this product was measured at λ<sub>max</sub> = 375 nm. The reaction proceeds quantitatively at room temperature. The linear calibration curve was constructed over range of (4.8 × 10<sup>-4</sup> - 1.6 × 10<sup>-2</sup>) mol/L of chromium ions with molar absorptivity of 2.90 × 10<sup>2</sup> and correlation coefficient R<sup>2</sup> = 0.9989. The calculated Sandell’s sensitivity value is 0.179 μg/cm<sup>2</sup>, the limits of detection (LOD) and the limit of quantification (LOQ) are found to be 3.74 × 10<sup>-5</sup> and 1.24 × 10<sup>-4</sup> mol/L, respectively. The method was successfully applied for determination of the chromium ion in aqueous solution. The stoichiometry of the reactions was determined molar combining ratio of 1:2 between chromium and ninhydrin.
