基于自研高效液相色谱-电感耦合等离子体质谱（HPLC-ICP-MS）仪，建立了测定地表水与废水中4种砷形态，包括三价砷[As （Ⅲ）]、二甲基砷（DMA）、一甲基砷（MMA）和五价砷[As （Ⅴ）]含量的方法。水样经0.45 μm滤膜过滤后，用Agilent G3154-65001色谱柱为固定相进行吸附，以NaH₂PO₃-Na₂EDTA溶液（pH 6）为流动相进行等度洗脱，分离后的目标物用ICP-MS测定，用碰撞反应模式来消除⁷⁵ArCl⁺对⁷⁵As的干扰。结果表明：三价砷、二甲基砷、一甲基砷和五价砷等4种砷形态可在7 min内完成出峰，其质量浓度均在0.1~10.0 μg·L^-1内与其对应的信号值呈线性关系，检出限（3.143s）分别为0.34，0.18，0.11，0.17 μg·L^-1。对实际样品进行加标回收试验，回收率为91.8%~110%，测定值的相对标准偏差（n=6）小于6.0%。在2种水样中检出了五价砷，其均低于GB 3838-2002规定的限值（50 μg·L^-1）。将本方法同相关文献方法进行比对，方法验证结果基本处于同一水平。

A method for determination of 4 arsenic species, including, As(Ⅲ), DMA, MMA and As(Ⅴ), in surface water and sewage was developed based on self-developed combined instrument of high performance liquid chromatography (HPLC)-inductively coupled plasma mass spectrometry (ICP-MS). Sample of water was filtered by 0.45 μm filter membrane, and the 4 arsenic species were adsorbed with Agilent G3154-65001 chromatographic column as stationary phase, and eluted isocratically by a mixture solution (pH 6) composed of NaH₂PO₃ and Na₂EDTA as mobile phase. Targets obtained were detected by ICP-MS, and the collision reaction mode was used to eliminate the interference of ⁷⁵ArCl⁺ to ⁷⁵As. The results showed that As(Ⅲ), DMA, MMA and As(Ⅴ) could be separated within 7 min, and linearity ralationships between mass concentrations of 4 arsenic species response values were kept in the same range of 0.1-10.0 μg·L^-1, with detection limits (3.143s) of 0.34, 0.18, 0.11, 0.17 μg·L^-1, respectively. Test for recovery was made by standard addition method on actual samples, giving values of recovery in the range of 91.8%-110% and RSDs of the determined values less than 6.0%. As(Ⅴ) was detected in 2 water samples, and its content was lower than the limit (50 μg·L^-1) of GB 3838-2002. The proposed method was compared with related reference methods, and results of mtehod verification were basically at the same level.