新型薄膜扩散梯度装置定量测量水环境中重金属形态  

New Diffusive Gradients in Thin-films Device for Quantitative Measurement of Heavy Metals in Water

作　　者：隋殿鹏[1] 李晶[2] 张岗[1] 刘金秀[2] 范洪涛[2] 孙挺[1] 

机构地区：[1]东北大学化学系,沈阳110004 [2]沈阳化工大学应用化学学院,沈阳110142

出　　处：《高等学校化学学报》2013年第5期1132-1138,共7页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金(批准号:21107076);辽宁省博士科研启动基金(批准号:20111048);辽宁省高等学校优秀人才支持计划(批准号:LJQ2012)资助

摘　　要：采用以纤维素透析膜为扩散相,0.05 mol/L羧甲基纤维素钠(CMC)溶液为结合相的薄膜扩散梯度(DGT)装置(CMC-DGT)定量累积和测量水溶液中Cu2+,Cd2+和Pb2+的有效态;考察了pH值和离子强度对CMC-DGT累积Cu2+,Cd2+和Pb2+的影响以及不同配体(乙二胺四乙酸二钠、单宁酸和黄腐酸)对重金属有效态的影响;测量了外加标的天然水和工业废水中重金属的有效态浓度;并比较了不同结合相DGT装置对同一水体中重金属的有效态浓度.实验结果表明,0.05 mol/L CMC溶液对Cu2+,Cd2+和Pb2+累积容量分别为0.24,0.11和0.45 mg/mL;定量累积的最佳pH值范围分别为3.7～8.0,4.7～9.0和4.7～8.0;随着离子强度的增大,CMC-DGT对Cu2+,Cd2+和Pb2+的累积容量下降;CMC-DGT能够定量地累积配制水中的游离Cu2+,Cd2+和Pb2+,回收率分别为92.1%,100.6%和96.4%;当有配体存在时,随着配体浓度的增大,CMC-DGT测量的Cu2+,Cd2+和Pb2+有效态的浓度随之下降;在过滤工业废水、河水和湖水中,不同结合相DGT装置对重金属有效态的测量值不同.结果表明,CMC可作为DGT技术新的液态结合相.Measurement of labile CuE＋, Cd2＋ and Pb by diffusive gradients in thin-films（DGT） device using 0. 05 mol/L solution of carboxymethyl cellulose sodium （ CMC ） as the binding phases and cellulose acetate dialysis membrane as the diffusive layer（CMC-DGT） was systemically investigated. The effects of pH, ionic strength on the binding capacity of CMC-DGT and ligands（ EDTA, tannic acid and fulvic acid） on the labile metals were investigated. Comparison of CMC-DGT device with PSS-DGT device for the measurement of labile Cu2＋, Cd2＋ and Pb2＋ in spiked waters was assessed. The binding capacities of CMC-DGT for Cu2＋, Cd2＋ and Pb2＋ were 0. 24, 0. 11 and 0. 45 mg/mL, respectively. Optimal pH ranges of CMC-DGT for CuE＋, Cd2＋ and Pb2＋ were 3.7--8.0, 4. 7--9. 0 and 4. 7--8.0, respectively. The binding capacities of CMC-DGT for Cu2＋, Cd2＋ and pb2＋decreased with the enhancement of ionic strengths in bulk solution. The Cu2＋, Cd2＋and Pb2＋ concentrations were determined accurately and simultaneously in synthetic solution by CMC-DGT （recoveries 92. 12% for CuE＋, 100. 6% for Cd2＋ and 96. 43% for pb2＋）. The labile concentrations of Cu2＋, Cd2＋ and Pb2＋ by CMC-DGT decreased with the enhancement of ligands concentrations. The measured values of labile Cu2＋, Cd2＋ and Pb2＋ concentrations by CMC-DGT were obviously more than that of PSS-DGT in spiked river water, spiked industrial wastewater and spiked lake water. Results indicated that CMC-DGT showed good prospect for the measurement of labile Cu2＋, Cd2＋ and Pb2＋ in waters.

关 键 词：薄膜扩散梯度 羧甲基纤维素钠 有效态 CU2+ Cd2+ PB2+ 

分 类 号：O653[理学—分析化学]