Determination of cadmium in high salt content matrices by flow injection cold vapor atomic absorption spectrometry


Abstract: Flow injection cold vapor atomic absorption spectrometry (FI-CVAAS) was used for determination of cadmium in high salt matrices such as dialysis concentrates and textile leach solutions. The parameters such as acidity, concentration of reducing agent, reaction coil length, and carrier gas flow rate were investigated to obtain the best sensitivity. No significant background signal was observed even at high salt concentrations. Under the optimized conditions the limit of detection value (3s_b m^{-1}, where s_b is the standard deviation of the blank signals and m is the slope of the calibration graph) was found to be 0.05 ng mL^{-1} for an injection volume of 250 \mu L and the precision in terms of relative standard deviation was 3.2% using 11 consecutive measurements of 0.5 ng mL^{-1} standard. The standard addition method was used for quantitation. The accuracy of the method was tested using ETAAS as a comparison method and a certified reference material (Waste Water EU-L-1). In both cases, the results were in good agreement at 95% confidence level. The concentrations of cadmium in textile product leach solutions were found to be below the limit value assigned by Oeko-Tex standards.

Keywords: Cadmium, chemical vapor generation, dialysis concentrates, artificial sweat, textile leachates

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