铊作为剧毒的重金属元素, 具有较强的蓄积性、 潜伏性和迁移性, 含铊矿床的开采及其工业三废的大量排放, 都可导致铊进入地表环境, 参与到土壤圈、 水圈、 大气圈、 生物圈物质循环, 并逐步在土壤和水体中富集, 破坏生态环境, 最终会通过食物链危及人体健康。 近年, 水质铊污染突发事件时有发生, 水环境铊的分析技术也成为铊分析技术研究的热点, 但多集中在实验室分析方法的改进方面, 水质铊在线监测分析方面的研究甚少。 而实验室分析方法在运输、 保存过程中难免有污染、 损失等; 且在数据时效性上也导致了一定的滞后, 很难应用于水体铊的应急监测分析, 从而影响了污染事故的分析和处置, 成为处置污染事故的最大瓶颈。 为了快速、 准确响应水质铊现场监测, 开展的水质在线监测技术研究对水质铊元素监测具有重要的应用意义, 可以实现水体铊污染的监测与预警, 进而有效降低因环境铊污染引起的铊中毒的风险。 建立了一种基于三电极方法原理的水质铊监测新技术。 该方法所用仪器小型、 便携、 低成本, 不仅可用于铊污染事故应急现场监测, 还可以用于污染源监管、 地表水风险预警自动监测。 本文就仪器检出限、 正确度、 精密度、 方法比对、 现场应用等各项性能指标进行了验证。 实验表明, 该技术用于测定水质铊的方法检出限为0.02 μg·L^-1, 与ICP-MS仪的检出限一致; 用于测定铊标准溶液的相对误差范围为-5.5%~2.9%; 测定实际水样的相对标准偏差范围为0.60%~6.2%; 其加标回收率达到101%~127%。 当水样含量在0.08 μg·L^-1以上, 该方法在现场应急监测比对中, 与实验室ICP-MS法具有可比性, 表明该技术具有很好的适用性。

Thallium, as a highly toxic heavy metal element, has strong accumulation, latency and mobility. The mining of thallium-containing deposits and the massive discharge of industrial three wastes can lead thallium to enter the surface environment, participate in the material cycle of the soil sphere, hydrosphere, atmosphere and biosphere, gradually enrich soil and water, and destroy the ecological environment. It will eventually endanger human health through the food chain. In recent years, thallium pollution emergencies in water quality have occurred from time to time. The analysis technology of thallium in the water environment has also become the research hotspot of thallium analysis technology. However, most of them focus on improving laboratory analysis methods, and there is little research on on-site monitoring of thallium in water quality. However, the laboratory analysis methods inevitably have pollution and loss in the process of transportation and preservation; It also leads to a certain lag in data timeliness, which is difficult to be applied to the emergency monitoring of thallium in water, which affects the analysis and disposal of pollution accidents and becomes the biggest bottleneck in the disposal of pollution accidents. In order to quickly and accurately respond to the on-site monitoring of thallium in water quality, the research on on-line monitoring technology in water quality has important application significance for thallium monitoring, which can realize the monitoring and early warning of thallium pollution in water and effectively reduce the risk of thallium poisoning caused by thallium pollution. A new monitoring technique of thallium in water quality based on the principle of the three electrode method is established in this paper. The instrument used in this method is small, portable and low-cost. It can be used not only for on-site monitoring of thallium pollution accidents but also for monitoring pollution sources and surface water risk. In this paper, the detection limit, accuracy, precision, method comparison and field application of the instrument are verified. The experimental results show that the detection limit of the method for the determination of thallium in water is 0.02 μg·L^-1, which is consistent with the detection limit of the ICP-MS instrument; The relative error range of thallium standard solution is -5.5%~2.9%, and the range of relative standard deviation is 0.60%~6.2%, and the recovery of standard addition is 101%~127%. When the water sample content is above 0.08 μg·L^-1, the method is comparable with laboratory ICP-MS in the field emergency monitoring and comparison, which shows that the technique is very applicable.