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 ANOVAtreatments.
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.