Amatatongchai Maliwan, Sroysee Wongduan, Chairam Sanoe, Nacapricha Duangjai
Department of Chemistry and Center of Excellent for Innovation in Chemistry, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani 34190, Thailand; Flow Innovation-Research for Science and Technology Laboratories (FIRST Labs), Bangkok 10400, Thailand.
Department of Chemistry and Center of Excellent for Innovation in Chemistry, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani 34190, Thailand.
Talanta. 2015 Feb;133:134-41. doi: 10.1016/j.talanta.2014.07.055. Epub 2014 Jul 31.
A new approach is presented for sensitive and selective measurement of sulfite (SO3(2-)) in beverages based on a simple flow injection system with amperometric detection. In this work, the sulfite sensor was a glassy carbon electrode modified with multiwall carbon nanotubes-poly(diallyldimethylammonium chloride)-gold nanoparticles composites (CNTs-PDDA-AuNPs/GC). Electrochemical oxidation of sulfite with this electrode was first studied in 0.1M phosphate buffer (pH 7.0) using cyclic voltammetry. The results indicated that the CNTs-PDDA-AuNPs/GC electrode possesses electrocatalytic activity for the oxidation of sulfite with high sensitivity and selectivity. Sulfite was quantified using amperometric measurement with the new sensor at +0.4V vs Ag/AgCl in conjunction with flow injection. The linear working range for the quantitation of sulfite was 2-200 mg L(-1) (r(2)=0.998) with a detection limit of 0.03 mg L(-1) (3σ of blank) and an estimated precision of 1.5%.The proposed method was successfully applied to the determination of sulfite in fruit juices and wines with a sample throughput of 23 samples per hour.
本文提出了一种基于简单流动注射系统和安培检测法灵敏且选择性地测定饮料中亚硫酸盐（SO₃²⁻）的新方法。在这项工作中，亚硫酸盐传感器是用多壁碳纳米管 - 聚二烯丙基二甲基氯化铵 - 金纳米颗粒复合材料（CNTs - PDDA - AuNPs/GC）修饰的玻碳电极。首先在0.1M磷酸盐缓冲液（pH 7.0）中使用循环伏安法研究了该电极对亚硫酸盐的电化学氧化。结果表明，CNTs - PDDA - AuNPs/GC电极对亚硫酸盐的氧化具有电催化活性，灵敏度高且选择性好。使用新传感器在相对于Ag/AgCl为 +0.4V时结合流动注射进行安培测量来定量亚硫酸盐。亚硫酸盐定量的线性工作范围为2 - 200 mg L⁻¹（r² = 0.998），检测限为0.03 mg L⁻¹（空白的3σ），估计精密度为1.5%。所提出的方法成功应用于果汁和葡萄酒中亚硫酸盐的测定，每小时样品通量为23个样品。
