Determination of the Cadmium Ions from Aqueous Solution Using EDTA Functionalized Prunus Dulcis L. Peels by Solid-Phase Extraction Method.

In the present study, Prunus Dulcis L. Peels was modified with ethylenedinitrilo tetraacetic acid and used as the sorbent for the preconcentration of Cd(II) ions from aqueous media. To characterize the sorbent, scanning electron microscopy-energy dispersive X-ray spectrometer and Fourier transform infrared spectrometer analysis were used. The optimum preconcentration conditions such as pH, eluent type, sample volume, sample flow rate and foreign ions effect were determined. The mean recovery and relative standard deviation values were found to be 100.7 ± 1.5 and 4.01% for Cd(II) ions. The capacity of the sorbent was obtained 277.8 mg g-1 from the Langmuir isotherm model. The limit of detection was calculated as 0.216 µg L-1 (P.F:40). In order to test the accuracy and applicability of the method, certified reference material and spiked water samples were analyzed. The results demonstrated good agreement with the certified values (relative error < 10%).

Preconcentration of trace amount Cu(II) by solid-phase extraction method using activated carbon-based ion-imprinted sorbent.

In this study, preconcentration conditions of trace amounts of copper ions were investigated with solid-phase extraction (SPE) method by synthesizing activated carbon-based ion-imprinted sorbent (Cu(II)-IAC) with a novel and selective approach. Flame atomic absorption spectrometry (FAAS) was used for the determination of metal ions concentrations. For the characterization of the sorbents, scanning electron microscopy, energy dispersive X-ray (SEM/EDX) analysis, and Fourier transform infrared spectroscopy (FTIR) were used. Optimum conditions for the SPE procedure, various parameters such as pH value, eluent type and concentration, sample volume, sample flow rate, adsorption capacity, and selectivity were studied. The adsorption isotherm was analyzed by Freundlich and Langmuir isotherm, and the maximum adsorption capacity was found to be 142.9 and 312.5 mg/g for activated carbon-based nonimprinted (Cu(II)-non-IAC) and Cu(II)-IAC sorbents, respectively from the Langmuir isotherm. Limit of determination (LOD) and limit of quantification (LOQ) values were found to be 0.038 and 0.113 µg/L, respectively for Cu(II)-IAC sorbent, and the results were compared with the literature. The accuracy and validity of the proposed method were evaluated by the determination of Cu(II) ions from tap water samples and certified reference materials (CRMs) (soft drinking water ERML-CA021e and NIST 1643e) analysis. Good and quantitative recoveries were obtained for the spiked analysis.

Investigation of the Conditions for Preconcentration of Cadmium Ions by Solid Phase Extraction Method Using Modified Juglans regia L. Shells.

BACKGROUND: Juglans regia L. shells as agricultural waste can be considered as alternative sorbents to minimize the problems associated with heavy metal pollution. OBJECTIVE: In this study, J. regia shells (JRS) and JRS modified with hydrazine hydrate (JRS-HH) were used as sorbents and compared for the preconcentration of Cd(II) ions from aqueous solution. METHODS: For the characterization of sorbents, scanning electron microscopy and energy dispersive X-ray (SEM/EDX) analysis and Fourier transform infrared (FTIR) spectroscopy were used. For preconcentration, the solid phase extraction (SPE) technique was used. Preconcentration studies were performed by column method and pH, eluent type and concentration, sample volume, flow rate, and interfering ions effect were studied to determine the optimum column parameters. RESULTS: The limit of detection (LOD) of the sorbents (JRS and JRS-HH) are 0.31 and 0.18 µg/L, respectively. According to the Langmuir isotherm model for both sorbents, for JRS KL = 0.030 L/mg, R2 = 0.992, 0.016 L/mg, and for JRS-HH KL = 0.016 L/mg, R2 = 0.998 and maximum adsorption capacities of the sorbents were found to be as 29.6 and 65.7 mg/g, respectively. The mean recoveries and RSD values at a 95% confidence level (N = 6) for Cd(II) were 100.9% and 3.42, and 100.6% and 3.79, for the JRS and JRS-HH sorbents, respectively. CONCLUSIONS: Using this method good results were obtained when compared with those in the literature and the proposed method was successfully applied to the analysis of the certificated reference material (NIST 1640). HIGHLIGHTS: JRS are an effective and inexpensive sorbent for the preconcentration of metal ions when modified. Thus, low-cost agricultural wastes are both recovered and have an economic value.