离子色谱-脉冲安培法测定空气中微量硫化氢  

Ion chromatography⁃pulsed amperometry method for determination of trace hydrogen sulfide in air

作　　者：高晓静 倪彤 沈睿 施超欧 GAO Xiaojing;NI Tong;SHEN Rui;SHI Chaoou(Analysis and Testing Center,School of Chemistry and Molecular Engineering,East China University of Science and Technology,Shanghai 200237,China)

机构地区：[1]华东理工大学化学与分子工程学院分析测试中心,上海200237

出　　处：《色谱》2024年第8期766-772,共7页Chinese Journal of Chromatography

基　　金：馆藏文物预防性保护风险防控关键技术研发示范项目(2020YFC1522500).

摘　　要：硫化氢(H_(2)S)是无色有毒气体,低浓度即有臭鸡蛋气味,浓度足够高时会麻痹嗅觉神经反而不易被察觉,人体长时间接触H_(2)S会使呼吸系统和中枢神经等受到严重损害。低浓度硫化氢可用离子色谱法检测,针对现有方法存在的问题,本文建立了一种准确、高效测定微量硫化氢气体的被动采样-离子色谱-脉冲安培定量分析方法。该法使用经典的IonPac AS7(250 mm×4 mm)阴离子交换色谱柱,并采用新型氢氧化钠-草酸钠淋洗液组合替代传统方法中氢氧化钠-乙酸钠淋洗液组合,优化脉冲安培检测电位参数,实现了低浓度硫化物的检测;探究提取稳定液的种类和含量对硫化物稳定性的影响,建立了硫化物的最佳保存条件。实验结果表明,硫化物在10~3000μg/L的范围内线性关系良好(相关系数r^(2)>0.999),检出限(S/N=3)和定量限(S/N=10)分别为1.53μg/L和5.10μg/L,保留时间和峰面积的相对标准偏差(RSD)均小于0.2%(n=6)。改进后方法稳定性好,操作要求低,硫化物峰形更为对称,基线噪声显著降低,且淋洗液试剂成本只有原来的10%,更适用于实际样品中低浓度硫化物的检测。采用250 mmol/L氢氧化钠-0.8%(质量分数)乙二胺四乙酸二钠稳定液可使硫化物稳定保存10 h以上,提高了回收率,使大批量、长时间检测更具可靠性。将新建立的方法应用于学校垃圾处理站附近空气中硫化氢含量的测定,检测结果均未超过国家规定限值,此法可满足硫化氢气体相关鉴定检测工作的要求。Hydrogen sulfide(H_(2)S)is a pervasive gaseous pollutant that emits the characteristic odor of rotten gas,even at low concentrations.It is generated during various industrial proces⁃ses,including petroleum and natural gas refining,mining operations,wastewater treatment ac⁃tivities,and refuse disposal practices.According to statistics from the World Health Organiza⁃tion(WHO),over 70 occupations are exposed to H_(2)S,rendering it a key monitoring factor in occupational disease detection.Although H_(2)S has legitimate uses in the chemical,medical,and other fields,prolonged exposure to this gas can cause severe damage to the respiratory and central nervous systems,as well as other organs in the human body.Moreover,the substantial release of H_(2)S into the environment can lead to significant pollution.This noxious substance has the potential to impair soil,water,and air quality,while disrupting the equilibrium of the sur⁃rounding ecosystems.Therefore,sulfide has become one of the most commonly measured sub⁃stances for environmental monitoring worldwide.Achieving the stable enrichment and accurate detection of low⁃level H_(2)S is of great significance.Common methods for detecting this gas in⁃clude spectrophotometry,chemical analysis,gas chromatography,rapid field detection,and ion chromatography.Although these methods provide relatively reliable results,they suffer from limitations such as high detection cost,low recovery,lack of environmental friendliness,and imprecise quantification of low⁃concentration H_(2)S.Furthermore,the sampling processes in⁃volved in these methods are complex and require specialized equipment and electrical devices.Additionally,approximately 20%of the sulfides in a sample are lost after 2 h in a conventional alkaline sodium hydroxide solution,causing difficulties in preservation and detection.In this study,an accurate,efficient,and cost⁃saving method based on ion chromatography⁃pulse amperometry was developed for H_(2)S determination.A conventional IonPac AS7(250 mm×4 m

关 键 词：离子色谱 安培检测 硫化物 电位 草酸钠 

分 类 号：O658[理学—分析化学]