Online Preconcentration and Determination of Trace Levels Cadmium in Water Samples Using Flow Injection Systems Coupled with Flame AAS

Abstract

A rapid and sensitive method for the determination of trace levels cadmium in water samples by flame atomic absorption spectrometry was developed. It is based on the online sorption of Cd(II) ions on a microcolumn packed with HCl treated bamboo charcoal. In a pH range of 5.0 -7.5, Cd(II) ions were effectively retained on the microcolumn, which exhibited fast kinetics, permitting the use of high sample flow rates up to at least 12.8 mL/min without the loss of retention efficiency. The retained Cd(II) ions were quantitatively eluted with HCl (2.0 mol/L) for an online determination. With a preconcentration time of 80 s at a sample loading flow rate of 8.6 mL/min, a sensitivity enhancement factor of 63 was obtained compared with the slope of the linear portion of the calibration curves before and after preconcentration. The calibration graph using the preconcentration system for cadmium was linear with a correlation coefficient of 0.9997, at levels from 1 -40 ng/mL. The precision (RSD) for 11 replicate measurements were 3.2% for the determination of 5 ng/mL Cd(II) and 1.8% for 20 ng/mL Cd(II), respectively, and the detection limit (3s) was 0.36 ng/mL. The accuracy was assessed through the determination of a certified reference material, and also through recovery experiments.

Solid-phase extraction of heavy metal ions on bucky tubes disc in natural water and herbal plant samples

“…Recovery, % Pb Fe 1.0 mol L −1 HNO 3 96 ± 1 a 96 ± 1 2.0 mol L −1 HNO 3 97 ± 2 9 8 ± 2 3.0 mol L −1 HNO 3 100 ± 0 9 5 ± 1 1.0 mol L −1 HCl 100 ± 1 9 8 ± 2 2.0 mol L −1 HCl 98 ± 2 9 5 ± 1 3.0 mol L −1 HCl 95 ± 1 9 6 ± 2 a Mean ± standard deviations the solid-phase extraction studies (Anilan et al 2010;Zhao et al 2010;Soylak and Dogan 1996;Ghaedi et al 2009a, b). The influences of sample volume on the recoveries of Fe(III) and Pb(II) on the BTs disc were investigated by using model solutions.…”

Amberlite IR-120 Modified with 8-Hydroxyquinoline as Efficient Adsorbent for Solid-Phase Extraction and Flame Atomic Absorption Determination of Trace Amounts of Some Metal Ions

“…The pH of the sample solutions plays a critical role on quantitative adsorption and recovery of trace elements on hydrophobic absorbents [31][32][33][34]. The effect of pH on the sorption efficiency of understudy metals ion in test solution was investigated by passing sample solution with pH in the range of 3-7 through the column at optimum value, and respective results are presented in Fig.…”

On‐line Solid Phase Extraction of Copper in Water Samples with Flow Injection Flame Atomic Absorption Spectrometry

“…Among the stationary phases usually used in FI-online solid phase extraction (SPE) for preconcentration of heavy metals, we can found C 18 [8], ion exchange resins [9,10], modified silica gel [11], activated carbon [12,13], Amberlite XAD-2 [1,14], XAD-4 [15,16], polyurethane foam [17], polytetrafluoroethylene turnings [18], knotted reactor [19], chitosan [20], synthetic zeolites [21], chromosorb 102 [22], surfactant coated alumina [3], cotton [23], and bamboo charcoal [24].…”