含有固定化氨基酸甜菜碱的高性能硝酸盐选择性电极作为传感器。

High-performance nitrate-selective electrodes containing immobilized amino acid betaines as sensors.

作者信息

Le Goff Thierry, Braven Jim, Ebdon Les, Scholefield David

机构信息

Plymouth Environmental Research Centre, Department of Environmental Sciences, University of Plymouth, UK.

出版信息

Anal Chem. 2002 Jun 1;74(11):2596-602. doi: 10.1021/ac010985i.

DOI:10.1021/ac010985i

PMID:12069243

Abstract

Ten nitrate-selective electrodes based upon rubbery membranes containing various betaine salts as sensors covalently bound to a cross-linked polystyrene-block-polybutadiene-block-polystyrene (SBS) polymer have been produced. The membranes were robust, highly selective, and effective over a pH range of 2-8. The best nitrate-selective electrode fabricated contained 10% m/m dicumyl peroxide, 40% 2-nitrophenyloctyl ether, 6.5% triallyl leucine betaine chloride and 43.5% SBS. The characteristics of this electrode were a linear Nernstian range of 1 x 10(-1) to 5 x 10(-6) mol dm(-3) NO3-, a limit of detection of 3.4 x 10(-7) mol dm(-3) NO3-, and a selectivity coefficient for nitrate against chloride, K(NO3-,Cl-)pot, of 3.4 x 10(-3). These figures represent a significant improvement on current commercial nitrate sensors. Response times were 1 min or less; stability of response and electrode lifetime in continuous use was also very satisfactory.

摘要

已制备出十种基于含各种甜菜碱盐的橡胶状膜的硝酸盐选择性电极，这些电极作为传感器与交联聚苯乙烯-嵌段-聚丁二烯-嵌段-聚苯乙烯（SBS）聚合物共价结合。这些膜坚固耐用、选择性高，在pH值2至8的范围内有效。所制备的最佳硝酸盐选择性电极含有10% m/m的过氧化二异丙苯、40%的2-硝基苯基辛基醚、6.5%的三烯丙基亮氨酸甜菜碱氯化物和43.5%的SBS。该电极的特性为：能斯特线性范围为1×10⁻¹至5×10⁻⁶ mol dm⁻³ NO₃⁻，检测限为3.4×10⁻⁷ mol dm⁻³ NO₃⁻，硝酸盐对氯离子的选择性系数K(NO₃⁻,Cl⁻)pot为3.4×10⁻³。这些数据表明相对于目前的商用硝酸盐传感器有显著改进。响应时间为1分钟或更短；连续使用时响应的稳定性和电极寿命也非常令人满意。