硫化氢(H2S)是一种普遍存在的气态污染物,散发着腐烂气体的特征气味,即使在低浓度。它是在各种工业过程中产生的,包括石油和天然气精炼,采矿作业,废水处理活动,和垃圾处理做法。根据世界卫生组织(WHO)的统计,超过70个职业暴露于H2S,使其成为职业病检测的关键监测因素。尽管H2S在化学品中具有合法用途,medical,和其他领域,长时间接触这种气体会对呼吸系统和中枢神经系统造成严重损害,以及人体的其他器官。此外,H2S大量释放到环境中会导致严重的污染。这种有毒物质有可能损害土壤,水,空气质量,同时破坏了周围生态系统的平衡。因此,硫化物已成为世界范围内最常用的环境监测物质之一。实现低浓度H2S的稳定富集和准确检测具有重要意义。检测这种气体的常用方法包括分光光度法,化学分析,气相色谱法,快速现场检测,和离子色谱法。尽管这些方法提供了相对可靠的结果,它们受到高检测成本等限制,回收率低,缺乏环境友好,和低浓度H2S的不精确定量。此外,这些方法涉及的采样过程很复杂,需要专门的设备和电气设备。此外,在常规碱性氢氧化钠溶液中2小时后,样品中的硫化物损失约20%,造成保存和检测困难。在这项研究中,一个准确的,高效,建立了基于离子色谱-脉冲安培法测定H2S的节约成本的方法。使用常规的IonPacAS7(250mm×4mm)阴离子交换柱,并使用基于氢氧化钠和草酸钠的新洗脱剂代替原来的氢氧化钠-乙酸钠洗脱剂。分析了影响该方法分离和检测性能的主要因素,包括脉冲电流检测电位参数和积分时间,以及稳定溶液中添加剂的类型和含量,进行了优化。结果表明,该方法在10~3000μg/L之间具有良好的线性关系,相关系数(r2)高达0.999。检出限(S/N=3)和定量限(S/N=10)分别为1.53和5.10μg/L,分别。硫化物的峰面积和保留时间的相对标准偏差(RSD)小于0.2%(n=6)。新方法表现出优异的稳定性,试剂成本降低高达90%。与常规离子色谱-脉冲安培法相比,该方法更适用于实际样品中低浓度硫化物的检测。硫化物在250mmol/L氢氧化钠-0.8%(质量分数)乙二胺四乙酸二钠盐溶液中有效保持超过10h。新型稳定剂显着提高了大规模和长期检测的可靠性。通过将该系统与徽章型无源采样器相结合,研究了该方法的回收率。这种采样方法不需要电源设备;价格低廉,操作简单,并且可以在不需要技术人员的情况下实现长期采样。此外,它可以克服污染物浓度短期变化的影响。采样结果对超清室内大规模无干预污染物监测具有较高的参考价值,博物馆柜台,和其他地方。结果表明,空白样品的方法回收率大于95%,样品加标准溶液的回收率为80%。最后,新建立的方法用于确定通过学校垃圾站被动采样收集的空气样品中的H2S含量。测量结果未超过国家限值。
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 processes, including petroleum and natural gas refining, mining operations, wastewater treatment activities, and refuse disposal practices. According to statistics from the World Health Organization (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 surrounding ecosystems. Therefore, sulfide has become one of the most commonly measured substances 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 include 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 involved 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 3000 μg/L, with correlation 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 exhibited excellent stability, with up to 90% reduction in reagent costs. Compared with conventional 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 maintained 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 devices; 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 pollutant 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 garbage stations. The measured results did not exceed the national limit.