材料期刊网

建立了一种流动注射、紫外光解／气膜扩散净化与小柱富集、离子色谱-脉冲安培检测自动分析废水中总氰与硫化物的方法。样品被混合到硫酸和次磷酸组成的混合酸载流中，内含适量的氨基磺酸、抗坏血酸、EDTA 与柠檬酸，经312 nm波长的紫外光解，使不同形态氰化物如 Fe（ CN）3—6等变成氰化氢，硫化物变成硫化氢，通过孔径0.45μm 的聚丙烯膜片扩散，由稀碱溶液吸收，Metrosep A PCC 1 HC／4.0富集柱捕获，IonPac AS7分析柱分离，银电极三电位波形脉冲积分安培检测。总氰与硫化物在0.5~1000μg／L范围内线性关系良好（相关系数分别为0.9989与0.9997），回收率在93％~102％，检出限（100μL进样，信噪比为5）为0.5 μg／L 与1.0μg／L。利用该方法每小时可做6个样品，部分实际样品的测定结果与标准方法的测定结果具有较好的一致性。

An automated system for the determination of total cyanides and sulfides in wastewater has been developed using flow injection,ultraviolet( UV)photo-dissociation,gas-membrane diffusion,column trapping,ion chromatography separation and pulsed amperomet-ric detection. When the sample was mixed with sulfuric acid and hypophosphorous acid medium containing the appropriate amount of sulfamic acid,ascorbic acid,EDTA and citric acid,met-al-cyanide complexes such as Fe( CN )3—6 can be photo-dissociated by 312 nm UV light,which results in hydrogen cyanide( HCN)and similarly,sulfides release hydrogen sulfide( H2S). These products were diffused through a 0. 45 μm hydrophobic porous polypropylene membrane and were then absorbed in the dilute NaOH solution,concentrated with a Metrosep A PCC 1 HC/4. 0 column, separated on an IonPac AS7 column, and finally detected by the pulsed amperometric detector with Ag electrode. The total cyanides and sulfides were good linear in the range of 0. 5—1 000 μg/L with correlation coefficients of 0. 998 9 and 0. 999 7 respectively. The recoveries were 93%—102% and the limits of detection were 0. 5 μg/L for total cyanides and 1. 0 μg/L for sulfides under the conditions of the sample volume of 100 μL and the signal to noise ratio of 5. The sample throughput of the system was six samples per hour. The results from this new method have been compared with the ones obtained with the standard method, which shows a good agreement.