title: Application of l-cystine modified zeolite for preconcentration and determination of ultra-trace levels of cadmium by flame atomic absorption spectrometry.
abstract: A very convenient, sensitive and precise solid phase extraction (SPE) system was developed for enrichment and determination of ultra-trace of cadmium ion in water and plant samples. This method was based on the retention of cadmium(II) ions by l-cystine adsorbed in Y-zeolite and carry out in a packed mini-column. The retained cadmium ions then were eluted and determined by flame atomic absorption spectrometry. The scanning electron microscopy (SEM), powder X-ray diffraction (XRD) and Fourier Transform Infrared (FT-IR) spectroscopy techniques were applied for the characterization of cystine modified zeolite (CMZ). Some experimental conditions affecting the analytical performance such as pH, eluent type, concentration of sample, eluent flow rate and also the presence of interfering ions were investigated. The calibration graph was linear within the range of 0.1-7.5ngmL(-1) and limit of detection was obtained 0.04ngmL(-1) with the preconcentration factor of 400. The relative standard deviation (RSD) was obtained 1.4%, indicating the excellent reproducibility of this method. The proposed method was successfully applied for the extraction and determination of cadmium(II) ion in black tea, cigarette's tobacco and also various water samples.
authors: School of Chemistry, Damghan University, Damghan 3671641167, Iran.
authors: Seyyed Ahmad
authors: SA
authors: Rezvani
authors: School of Chemistry, Damghan University, Damghan 3671641167, Iran; Institute of Biological Science, Damghan University, Damghan 3671641167, Iran. Electronic address: soleymanpour@du.ac.ir.
authors: Ahmad
authors: A
authors: Soleymanpour
mesh_terms: D000327:Adsorption; D002104:Cadmium / Q000302:isolation & purification*; D028241:Camellia sinensis / Q000737:chemistry; D002413:Cations, Divalent; D003553:Cystine / Q000737:chemistry*; D015203:Reproducibility of Results; D052616:Solid Phase Extraction / Q000379:methods; D013054:Spectrophotometry, Atomic / Q000379:methods; D013237:Stereoisomerism; D014026:Nicotiana / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis; D017641:Zeolites / Q000737:chemistry*
chemical_list: D002413:Cations, Divalent; D014874:Water Pollutants, Chemical; D002104:Cadmium; D017641:Zeolites; D003553:Cystine
keywords: Cadmium; Flame atomic absorption spectrometry; Solid phase extraction; Zeolite; l-Cystine