|国家科技期刊平台
首页|期刊导航|色谱|离子色谱-脉冲安培法测定空气中微量硫化氢

离子色谱-脉冲安培法测定空气中微量硫化氢OA北大核心CSTPCDMEDLINE

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

中文摘要英文摘要

硫化氢(H2S)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H2S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10~3 000 μg/L的范围内线性关系良好(相关系数r2>0.999),检出限(S/N=3)和定量限(S/N=10)分别为1.53 μg/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(H2S)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 H2S,rendering it a key monitoring factor in occupational disease detection.Although H2S 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 H2S 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 H2S 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 H2S.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 H2S determination.A conventional IonPac AS7(250 mm ×4 mm)anion-exchange column was employed,and a new eluent based on sodium hydroxide and sodium oxalate was used to replace the original sodium hydroxide-sodium acetate eluent.The main factors influencing the separation and detection performance of the proposed method,including the pulse amperage detection potential parameters and integration time,as well as the type and content of additives in the stabilizing solution,were optimized.The results showed that the proposed method had a good linear relationship between 10 and 3 000 μg/L,with cor-relation coefficients(r2)of up to 0.999.The limits of detection(S/N=3)and quantification(S/N=10)were 1.53 and 5.10 μg/L,respectively.The relative standard deviations(RSDs)of the peak area and retention time of sulfides were less than 0.2%(n=6).The new method ex-hibited excellent stability,with up to 90%reduction in reagent costs.Compared with conven-tional ion chromatography-pulse amperometry,this method is more suitable for detecting low concentrations of sulfides in actual samples.Sulfides in a 250 mmol/L sodium hydroxide-0.8%(mass fraction)ethylenediaminetetraacetic acid disodium salt solution were effectively main-tained for over 10 h.The new stabilizer significantly improved the reliability of both large-scale and long-term detection.The recovery of the proposed method was investigated by combining the system with a badge-type passive sampler.This sampling method requires no power de-vices;it is inexpensive,simple to operate,and can realize long-term sampling without the need for skilled personnel.Moreover,it can overcome the influence of short-term changes in pollu-tant concentration.The sampling results have high reference value for large-scale intervention-less pollutant monitoring in ultraclean rooms,museum counters,and other places.The results demonstrated that the recovery of the proposed method was greater than 95%for the blank sample and 80%for the sample plus standard solution.Finally,the newly established method was applied to determine H2S levels in air samples collected via passive sampling at school gar-bage stations.The measured results did not exceed the national limit.

高晓静;倪彤;沈睿;施超欧

华东理工大学化学与分子工程学院分析测试中心,上海 200237

化学

离子色谱安培检测硫化物电位草酸钠

ion chromatography(IC)amperometric detectionsulfidepotentialsodium oxalate

《色谱》 2024 (008)

766-772 / 7

馆藏文物预防性保护风险防控关键技术研发示范项目(2020YFC1522500).Research and Development Demonstration of Key Technologies for Risk Prevention and Control in the Pre-ventive Protection of Cultural Relics(No.2020YFC1522500).

10.3724/SP.J.1123.2023.10028

评论