采用场强放大堆积-氢化物发生-原子荧光光谱法测定水中硒的含量。设计了场强放大堆积装置，在电场作用下，硒阴离子可以从水样中迁移到高电导率的富集液中而实现硒的富集。优化的试验条件如下：①电极距离为4 cm；②富集腔体积为3.0 mL；③富集液为磷酸盐缓冲溶液；④场电流为80 mA；⑤富集时间为8 min。硒的质量浓度在3.0~200 ng·L^-1内与其对应的荧光强度呈线性关系，检出限（3σ）为1.8 ng·L^-1。在20 ng·L^-1浓度水平进行加标回收试验，回收率为98.0%~106%。方法应用于国家标准样品GSBZ 50031-94的分析，测定值与认定值相符，测定值的相对标准偏差（n=5）为1.2%。

HG-AFS was applied to the determination of selenium in water with field-enanced stacking. A field-enhanced stacking equipment was developed. Under application of electric field, selenium anion was migrated from water sample solution to enrichment solution of higher conductivity and concentrated. The optimized conditions found were as follows: ① electrode distance was 4 cm; ② volume of enrichment cavity was 3.0 mL; ③ enrichment solution was PBS; ④ field current was 80 mA; ⑤ enrichment time was 8 min. Linear relationship between values of fluorescence intensity and mass concentration of selenium was kept in the range of 3.0-200 ng·L^-1, with detection limit (3σ) of 1.8 ng·L^-1. Tests for recovery were made by standard addition method at the concentration level of 20 ng·L^-1, giving values of recovery in the range of 98.0%-106%. The proposed method was applied to the analysis of national standard sample GSBZ 50031-94, giving result in consistency with the certified value with RSD (n=5) of 1.2%.