孙惠霞

摘 要：采用氢化物发生-原子荧光光谱法，对地下水、地表水、饮用水以及生活污水中的砷含量进行测定，对氢化物发生条件、载流酸类型、酸的浓度、还原掩蔽剂浓度等影响因素进行详细探讨，选出优化的测定条件：以5%的盐酸为载流酸性介质，以20 g·L-1的硼氢化钠（溶解于2 g·L-1的氢氧化钠稳定剂中）为还原剂，以50 g·L-1硫脲-抗坏血酸为还原掩蔽剂。在该测定条件下，砷的标准曲线浓度范围为0～20.0 μg·L-1，线性可达0.9999;方法检出限为0.02 μg·L-1;分别对不同浓度的砷标准溶液进行测定，其相对标准偏差（RSD）为1.06%～1.14%;对外购的标准样品进行测定，测定值在标准值的不确定度范围内;对实际水样进行加标回收实验，砷的加标回收率为96%～114%;表明该方法的精密度、准确度良好。

关键词：氢化物发生-原子荧光光谱法;砷;测定

Determination of arsenic in water by hydride generation atomic

fluorescence spectrometry

SUN Huixia

（Beijing Institute of Hydrogeology and Engineering Geology （Beijing Institute of Geo-Environment Monitoring）， Beijing 100195， China）

Abstract： Arsenic content in various water was determined by using hydride generation-atomic fluorescence spectrometry. The effect of hydride generation conditions， carrier acid type， acid concentration， and reductant masking agent concentration was discussed in detail and the optimized determination conditions were obtained. 5% hydrochloric acid was used as carrier acidic medium， 20 g·L-1 sodium borohydride （dissolved in 2 g·L-1 sodium hydroxide stabilizer） was used as reducing agent， and 50 g·L-1 thiourea-ascorbic acid was used as reductant masking agent. Under the optimized determination conditions， the concentration range of arsenic standard curve was 0 -20.0 μg·L-1， the linear correlation was 0.9999， and the method detection limit was 0.02 μg·L-1. The arsenic standard solutions of different concentration were continuously measured 7 times， and the relative standard deviations （RSD） were 1.06% -1.14%. The certified reference materials were tested， and the results of arsenic content were within the uncertain range of the standard value. The standard addition recovery experiment was carried out for different kinds of water， and the recovery rate was between 96% and 114%. The above results demonstrated good precision and accuracy of the determination method.

Keywords： hydride generation atomic fluorescence spectrometry; arsenic; determination

飲水安全与人民的身心健康息息相关，饮用水、地下水和地表水直接关系到人们日常的饮水安全，生活污水的排放也直接或间接对饮水安全造成危害。目前，我国一些地方的地下水中砷污染情况比较严重（邓安琪等，2017），世界卫生组织国际癌症研究机构于2012年将砷列为一级致癌物。因此，对此类水中毒理学指标砷含量的测定具有重要意义（王潇等，2019;金阳等，2015）。

砷含量的测定方法有多种，电感耦合-等离子体质谱法（李智明，2016）和原子荧光光谱法（张延妮等，2009）等方法应用较为广泛。氢化物发生-原子荧光光谱法（HG-AFS）是具有自主知识产权、技术超进口水平的分析技术（杭乐等，2019），其具有线性范围宽……