固态电化学气体传感器的最新发展

本文从固态电化学气体传感器的一般原理,着重评述了固态电化学气体传感器的分类依据及每类传感器的发展;并对极有应用潜力的第三类电化学气体传感器的发展水平及其方向进行了论述。     

我国突破电化学气体传感器核心技术

中科院长春应化所研发的“电化学气体传感器”创新成果，被评选为“2006年中国科学仪器及分析测试行业十大新闻”。该项成果已在我国环保、化工、矿山等行业广泛应用，标志着我国已突破了电化学气体传感器的核心技术。     

气体流动注射分析和连续流动分析系统的研究-二氧化硫气体的电化学测定

本文以电化学气体传感器为检测器,将流动注射技术直接用于二氧化硫气体分析.详细研究了气体流动体系的连接方式、气体流速以及体系中压强的变化对分析信号的影响,得到最佳连接方式,比较了载气流速对气体流动注射分析和连续流动分析的影响.气体流动注射分析法重现性较好,测定2890×10~(-6)mol/mol SO_2的相对标准偏差为0.7%(n=12),测定速度快,可达50样/时.连续流动分析能达到气体传感器的稳态响应信号,灵敏度较高     

改性Nafion膜在全固态二氧化硫气体传感器中的应用

研究了用改性Nafion膜在全固体电解质的全固态定位电解型SO2气体传感器。发现Nafion膜用硫酸处理后，膜的保水性增加，因此传感器的稳定性较好，进行寿命试验4个月，性能略有下降，有望成为一种能实际使用的气体传感器。     

脉冲电势调制型电化学气体传感器

根据暂态电化学原理 ,使用微电极并融合计算机控制的快速电势调制技术和数据采集、处理功能 ,提出并建立了一类全新的集信号提取、处理与结果显示等功能于一体的“脉冲电势调制型气体传感器” .在优化传感器性能及其新的功能开发和集成方面取得了重要进展 ,是一类为常规电化学气体传感器无法比拟而有发展前景的暂态电化学多组份气体传感器 .     

我国电化学气体传感器技术达到国际先进水平

由中国科学院长春应用化学研究所承担的电化学气体传感器研究项目不久前通过了技术鉴定。鉴定意见说：“这一研究成果标志着中国电化学气体传感器技术达到了国际先进水平。”     

荧光型二氧化硫光纤传感器的研究

本文描述了一种新的测量二氧化硫的荧光型光纤传感器。溶于内充液的奎宁被用作敏感物,通过气透膜将内充液与水溶液分开。传感器对二氧化硫的响应范围是3×10~(-6)～3×10~(-4)mol/L。报道了传感器的重现性、稳定性、响应时间和选择性。用该传感器测定了含二氧化硫的实际样品并与碘量法进行了比较。     

电化学脱氧核糖核酸传感器

本文对电化学脱氧核糖核酸（ＤＮＡ）传感器的原理，ＤＮＡ在电极表面的固定化，杂交指示剂的研究和电化学ＤＮＡ传感器的性能、分析应用及电化学石英晶体微天平ＤＮＡ传感器等方面的研究进展作了评述。提出了今后研究工作的方向。     

高灵敏度二氧化硫光纤传感器的研究

以奎宁为荧光试剂,通过改变传感液膜的组成及采用非稳态测量法,研制成功高灵敏度的二氧化硫光纤传感器,该传感器的线性响应范围为3.1×10^-7～7.8×10^-5mol/L,检测限达1.6×10^-7mol/L.研究了内充液中NaHSO₃浓度、内充液层厚度对该光纤传感器动态响应信号的影响,用该传感器测定了葡萄酒中游离二氧化硫的含量,结果令人满意.     

Organic Phase Cyclopentadienylnickelthiolate Sensor System for Electrochemical Determination of Sulfur Dioxide

A series of cyclopentadienylnickelthiolate complexes, [Ni(PBu₃)(η⁵‐C₅H₅)(SC₆H₄X‐4)] (X=F, Cl, Br, NH₂), were shown to express stable reversible electrochemical properties even after formation of SO₂ adducts in organic phase consisting of argon purged CH₂Cl₂/0.1 M [n‐Bu₄N][BF₄]. The formal potentials (E°′) values of the compounds ranged from 265 to 431 mV/Ag‐AgCl depending on the para substituent of the benzene thiolate ligand. Electrochemical, UV‐vis and ¹H NMR spectroscopic analyses show that the formation of SO₂ adducts causes the perturbation of the electronic density of the nickel metal center, indicated by shifts in the E°′ values of the Ni^II/III redox couple that is dependent on SO₂ concentration. The detection limits of the resulting organic phase electrochemical gas sensor system was as low as 0.56 ppm SO₂ for the fluoro complex, while the linear range was as high as 700–2000 ppm SO₂ for the amino complex.     

Electrochemical Oxidation Behavior of Nitrogen Dioxide for Gas Detection Using Boron Doped Diamond Electrodes

The electrochemical oxidation reaction of nitrogen dioxide (NO₂) using boron doped diamond (BDD) electrodes is presented. Cyclic voltammetry of NO₂ in a 0.1 M KClO₄ solution exhibits oxidation peaks at +1.1 V and +1.5 V (vs. Ag/AgCl) which are attributable to oxidation of HONO and NO₂⁻, respectively. Moreover, the pH and scan rate dependences were investigated to study the oxidation mechanism. A linear calibration curve was observed in the concentration range of ∼1 to 5 mM (R²=0.99) with a detection limit of 11.1 ppb (S/B=3) for HONO and 58.6 ppb (S/B=3) for NO₂⁻. In addition, the analytical performance was compared with those using glassy carbon, platinum and stainless steel as the working electrode.     

催化发光法同时测定空气中的甲醛、苯和二氧化硫

基于甲醛、苯和二氧化硫在纳米Ti3CeY2O11上的催化发光有交叉敏感现象,在3个波长处分别确定甲醛、苯和二氧化硫浓度与催化发光信号强度的响应关系,再依据发光信号强度的叠加性特征即可获取甲醛、苯和二氧化硫的准确浓度,据此建立了同时测定空气中甲醛、苯和二氧化硫的新方法.3个分析波长分别为420、535和680 nm,敏感材料表面温度为280℃,载气流速为130 mL/min.本方法对甲醛、苯和二氧化硫的检出限(3σ)分别为0.04、0.05和0.10 mg/m3,线性范围分别为0.08~75.60 mg/m3、0.10~101.40 mg/m3和0.30~115.00 mg/m3, 回收率分别为96.4%~103.7%、97.8%~102.5%和97.2%~103.3%.常见共存物,如乙醛、甲苯、硫化氢、氨、甲醇、乙醇和二氧化碳等不干扰测定.连续200 h通浓度均为50 mg/m3的甲醛、苯和二氧化硫混合气体,发光强度的相对偏差≤2%,表明此纳米级复合氧化物对甲醛、苯和二氧化硫的敏感性的寿命长.本方法充分利用了交叉敏感现象,可以实现空气中甲醛、苯和二氧化硫的在线分析.     

Detection of Sulfur Dioxide Using a Piezoelectric Quartz Crystal Microbalance

Abstract

Sulfur dioxide was detected and determined in air by a piezoelectric quartz crystal sensor coated with 4-aminoantipyrine 1-hydroxyetil-2-heptadecenyl imidazol (amine 220) solution (1:1 v/v in chloroform). The analytical response curve is linear over the concentration range from 0.70 to 5.0 ppm of SO₂. Good linearities (r = 0.9990, 0.9995 and 0.9968) and sensitivities (18.0, 33.4 and 50.7 Hz/ppm) were found, respectively for exposure times of 30, 60 and 90 seconds. The sensor can be used for more than six months without loss in sensitivity and presented good reversibility and reproducibility. Among some possible interferents tested, only nitrogen dioxide and moisture caused major frequency changes.     

Monitoring of Atmospheric Sulfur Dioxide by Fluorescence Monitoring System

A fluorescence monitoring system was used to measure gaseous sulfur dioxide at Taoyuan Agricultural Farm. A gas-diluting system and gas chromatograph equipped with a sulfur chemiluminescence detector used to audit the accuracy of diluted sulfur dioxide are described. The accuracy was ?8% and ?2%, respectively, for the preparation of 10 and 50 ppb SO₂ standard gas. The pattern of variation of SO₂ concentration at Taoyuan Agricultural Farm is reported. In summer at Taoyuan Agricultural Farm, the concentration of SO₂ varied with a pattern of night concentration (15-20 ppb) greater than that in the afternoon (0–2 ppb). Computer-analyzed wind trajectories in Taiwan for this pattern are reported.     

Electrochemical Sensor for Sulfite and Sulfur Dioxide Based on 3‐Aminopropyltrimethoxysilane Derived Sol‐Gel Composite Electrode

A new sol‐gel derived composite sensor has been developed for the determination of sulfite and sulfur dioxide using 3‐aminopropyltrimethoxysilane, ferrous sulfate and graphite powder by sol‐gel process. Cyclic voltammetry and amperometry studies revealed that the modified iron dispersed sol‐gel derived ceramic composite electrode exhibited excellent characteristics for the electrocatalytic oxidation of sulfite at a reduced potential of +0.35 V with good sensitivity and selectivity. The pH and the potential for sulfite estimation have been optimized. The sensor exhibited rapid and linear response to sulfite in the concentration range from 0.73 mg/L to 95.42 mg/L with a correlation coefficient of 0.997. The proposed sensor can be utilized for the determination sulfur dioxide after absorbing in a suitable medium and has promising characteristics such as, rapid response, good reproducibility and remarkable stability.     

一种用于食品中二氧化硫快速测定的样品前处理方法

提出了一种采用半微量蒸馏-半导体制冷技术的食品中二氧化硫快速提取的新方法, 研制出了可在15 min内完成二氧化硫提取的食品检测快速蒸馏提取装置. 采用本装置,  无需冷凝水和含汞吸收剂即可实现对样品中二氧化硫的蒸馏提取. 考察了蒸馏液酸度、   蒸馏液体积、 馏分收集体积和蒸馏提取时间对二氧化硫提取效率的影响. 研究结果表明,  采用该方法在30 min内即可完成对食品中二氧化硫的快速定量测定.