Determination of cadmium by flame-atomic absorption spectrometry after preconcentration on silica gel modified with cupferron

Abstract

Este trabalho descreve um método para a pré-concentração de cádmio com sílica gel modificada com cupferron e sua determinação por espectrometria de absorção atômica com chama. O efeito do pH, a quantidade do material adsorvente, a concentração de eluente, volume da amostra e quantidade do analito adsorvido foram otimizados. O efeito de interferentes foi avaliado para diversos íons mostrando que a extração de cádmio somente é afetada por Zn(II) e Cu(II), dependendo da concentração dos mesmos, mas pode ser minimizada pela adição de 0,05 mmol de KI. Foi obtido um fator de enriquecimento de até 30 vezes. Os limites de detecção e de quantificação foram de 0,5 µg L -1 (3σ) e 2,0 µg L -1 (10σ), respectivamente, com rsd de 1,1% (n=10). A exatidão foi avaliada com material de referência certificado e o resultado obtido (3,93 ± 0,01 µg g -1 ) concordou com o valor certificado (4,15 ± 0,38 µg g -1 ). O teor de cádmio em esmalte de unhas foi determinado, obtendo-se recuperações quantitativas para as amostras enriquecidas com o analito. O método proposto caracteriza-se pela simplicidade, eficiência e baixo custo.A method for the determination of cadmium by flame atomic absorption spectrometry (FAAS) after its preconcentration onto a column containing silica gel modified with cupferron was developed. The pH, amount of adsorbent material, concentration of eluent, volume of sample and amount of Cd were optimized. The effect of several foreign ions was also investigated and showed that the retention of cadmium depended on the amounts of Zn(II) and Cu(II) present and that these interferences could be overcome by using a 0.05 mmol KI. An enrichment factor of up to 30 was obtained , the LOD was 0.5 µg L -1 (3σ) and the LOQ was 2.0 µg L -1 (10σ) with rsd of 1.1% (n = 10). The accuracy of the proposed method was ascertained by using certified reference material and the obtained result (3.93 ± 0.01 µg g -1 ) agrees with the certified value (4.15 ± 0.38 µg g -1). The determination of Cd in nail polish showed quantitative recoveries for the spiked samples. The proposed method is characterized by simplicity, efficiency and low cost.

Applications of Amberlite XAD based Chelating resins in Online Pre concentration of metal ions

“…The chelating resins can be used in flow injection system with various detection methods like FAAS, ICP-AES, spectrophotometry, chemiluminescence and ICP-MS etc [26].There are various chelating resins have recently been used such as polyurethane foam [27][28][29][30][31][32][33][34][35], cellulose, silica gel [36][37][38][39][40][41][42], alumina [43][44][45][46][47][48], chitosan [49][50][51], carbon active [52] and polymeric resins like Amberlite etc. Amberlite XAD resins widely used to develop several chelating materials for preconcentration procedures due to its good physical and chemical properties such as porosity, high surface area, durability and purity.…”

Glassy carbon modified with triazol derivative for analysis of cadmium (II)

“…The modified electrodes are investigated by electrochemistry and x-ray photoelectron spectroscopy (XPS) [6], [7]. Important papers about Cd(II) ion analysis were evaluated using spectrophotometric methods and flame-atomic absorption spectrometry [8], [9]. Nonetheless, the tecniques have difficult methods to eliminate the excipients.…”

Determination of Some Trace Metals by FAAS after Solid-phase Extraction with Amberlite XAD-1180/TAN Chelating Resin

“…6,7 There are many methods for separation and preconcentration, such as ion-exchange, 8 liquid-liquid extraction, 9 coprecipitation 10,11 and solid-phase extraction. 12,13 Among these, solid phase extraction is commonly used, and is a very favorable technique. 14 In preconcentration studies performed by utilizing solid-phase extraction for trace metal ions, many natural and synthetic sorbent materials are used as the column filling material.…”

“…14 In preconcentration studies performed by utilizing solid-phase extraction for trace metal ions, many natural and synthetic sorbent materials are used as the column filling material. Among these, silica gel, 5,12 cellulose, 15,16 activated carbon, 17,18 Amberlite XAD resins, 19,20 biosorbents 21 and various polymers 22 are the most widely used support materials. It is necessary that the retention of metal ions on a solid sorbent for preconcentrating purposes occurs when using a solid-phase extraction procedure.…”