Spectrophotometric Method for Determination of Chromium Ion in Aqueous Solution Using Ninhydrin

Abstract

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 max = 375 nm. The reaction proceeds quantitatively at room temperature. The linear calibration curve was constructed over range of (4.8 × 10 −4 -1.6 × 10 −2 ) mol/L of chromium ions with molar absorptivity of 2.90 × 10 2 and correlation coefficient R 2 = 0.9989. The calculated Sandell's sensitivity value is 0.179 µg/cm 2 , the limits of detection (LOD) and the limit of quantification (LOQ) are found to be 3.74 × 10 −5 and 1.24 × 10 −4 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.

Plant extract mediated synthesis of ZnO and CeO2 nanoparticles for spectrofluorometric assay of omeprazole and domperidone in pharmaceuticals

“…Electrochemical methods are also fast to perform and document their results in the form of electrical signals, but they have some analytical weaknesses that require reducing their toxicity to protect the environment. Nevertheless, spectrofluorometric methods have received considerable opportunities and attention as quantification measurement techniques due to their ease of use, high speed, stability, and sensitivity [ 14 , 15 ].…”