New Approach for an On-Line Turbidimetric Determination of Cadmium (II) in Different River Water Via the Use of A homemade Ayah 6SX1-T-2D Solar-Continuous Flow Injection Analyser

Abstract

A newly developed analytical method characterized by its speed and sensitivity for the determination of cadmium (II) in aqueous solution in three randomly chosen samples from river water at different locations via turbidimetric measurement by Ayah 6SX1-T-2D Solar - CFI analyser. The method is based on the formation of yellowish white precipitate for the complex Cd3[Fe(CN)6]2 by direct reaction of the cadmium (II) with potassium hexacyano ferrate (III) in aqueous medium. Turbidity was measured via the reflection of incident light that collides on the surfaces precipitated particles at 0-180o. Chemical and physical parameters were investigated. Linear dynamic of cadmium (II) is ranged from 0.05-12 mmol.L-1, with correlation coefficient r = 0.9951. The limit of detection 25.29 ng/ sample from the step wise dilution for the minimum concentration in the linear dynamic range of the calibration graph with RSD % lower than 1.5% for 8 mmol.L-1 (n=5) concentration of cadmium (II). The method was applied successfully for the determination of cadmium (II) in three river samples. A comparison was made between the proposed method of analysis with the classical method (HANNA instrument for turbidity measurement) using the standard additions method via the use of ANOVA-treatments. It was noticed that there is a significant difference at α=0.05 between the two methods at level < 0.05 was obtained. On that basis the new method can be accepted as an alternative analytical method.