SCI和EI收录∣中国化工学会会刊

Chin.J.Chem.Eng. ›› 2014, Vol. 22 ›› Issue (4): 480-488.DOI: 10.1016/S1004-9541(14)60055-0

• MATERIALS AND PRODUCT ENGINEERING • Previous Articles    

PVC Membrane Selective Electrode for Determination of Cadmium(Ⅱ) Ion in Chocolate Samples

Sulekh Chandra1, Deepshikha Singh1,2, Anjana Sarkar2   

  1. 1 Department of Chemistry, Zakir Husain Delhi College, University of Delhi, New Delhi 110002, India;
    2 School of Applied Sciences, Netaji Subhas Institute of Technology, University of Delhi, New Delhi 110075, India
  • Received:2012-08-12 Revised:2013-01-08 Online:2014-04-04 Published:2014-04-28

PVC Membrane Selective Electrode for Determination of Cadmium(Ⅱ) Ion in Chocolate Samples

Sulekh Chandra1, Deepshikha Singh1,2, Anjana Sarkar2   

  1. 1 Department of Chemistry, Zakir Husain Delhi College, University of Delhi, New Delhi 110002, India;
    2 School of Applied Sciences, Netaji Subhas Institute of Technology, University of Delhi, New Delhi 110075, India
  • 通讯作者: Sulekh Chandra

Abstract: Benzil bis(carbohydrazone) (BBC) is prepared and explored as new N—N Schiff's base, which plays the role of an excellent ion carrier in the construction of a Cd(Ⅱ) ion membrane sensor. The tris(2-ethylhexyl) phosphate best performance corresponds to a membrane composition of 30% poly (vinyl chloride), 65% (TEHP), 3.5% BBC and 1.5% tetradodecyl-ammoniumtetrakis(4-chlorophenyl) borate (ETH 500). This sensor shows very good selectivity and sensitivity towards cadmium ion over a wide variety of cations, including alkali, alkaline earth, transition and heavy metal ions. The effect of membrane composition, selectivity, pH and influence of additive on the response properties of electrode were investigated. The response mechanism was discussed in the view of UV-spectroscopy. The electrode exhibits a Nernstian behavior (with slope of 29.7 mV per decade) over a very wide concentration range from 1.0×10-1 to 1.0×10-8 mol·L-1 with a detection limit of 3.2×10-8 mol·L-1. It shows relatively fast response time in whole concentration range (<8 s) and can be used for at least 10 weeks in the pH range of 2.0-9.0. The proposed sensor is successfully used for the determination of cadmium in different chocolate samples and as indicator electrode in titration with ethylene diamine tetraacetate (EDTA).

Key words: benzil bis(carbohydrazone), ionophore, Cd(Ⅱ) ion membrane sensor, selectivity coefficient, additive

摘要: Benzil bis(carbohydrazone) (BBC) is prepared and explored as new N—N Schiff's base, which plays the role of an excellent ion carrier in the construction of a Cd(Ⅱ) ion membrane sensor. The tris(2-ethylhexyl) phosphate best performance corresponds to a membrane composition of 30% poly (vinyl chloride), 65% (TEHP), 3.5% BBC and 1.5% tetradodecyl-ammoniumtetrakis(4-chlorophenyl) borate (ETH 500). This sensor shows very good selectivity and sensitivity towards cadmium ion over a wide variety of cations, including alkali, alkaline earth, transition and heavy metal ions. The effect of membrane composition, selectivity, pH and influence of additive on the response properties of electrode were investigated. The response mechanism was discussed in the view of UV-spectroscopy. The electrode exhibits a Nernstian behavior (with slope of 29.7 mV per decade) over a very wide concentration range from 1.0×10-1 to 1.0×10-8 mol·L-1 with a detection limit of 3.2×10-8 mol·L-1. It shows relatively fast response time in whole concentration range (<8 s) and can be used for at least 10 weeks in the pH range of 2.0-9.0. The proposed sensor is successfully used for the determination of cadmium in different chocolate samples and as indicator electrode in titration with ethylene diamine tetraacetate (EDTA).

关键词: benzil bis(carbohydrazone), ionophore, Cd(Ⅱ) ion membrane sensor, selectivity coefficient, additive