Chelex 100树脂固相萃取-电感耦合等离子体原子发射光谱法测定高氯高盐废水中6种重金属元素

Determination of Six Heavy Metal Elements in High Chloride and High Salt Wastewater by Solid Phase Extraction with Chelex 100 Resin-ICP-AES

用Chelex 100树脂固相萃取法分离高氯高盐废水中的铜、铅、锌、镍、镉和锰等6种目标元素,用电感耦合等离子体质谱法(ICP-MS)优化固相萃取条件,用电感耦合等离子体原子发射光谱法(ICP-AES)测定目标元素的含量。高氯高盐废水样品经硝酸消解后,用乙酸盐缓冲溶液(pH 6.5)定容。预先填充好Chelex树脂的固相萃取小柱,用0.5 mol·L^(-1)乙酸铵溶液活化,以1 mL·min^(-1)速率加入样品溶液10 mL后,用0.5 mol·L^(-1)乙酸铵溶液和水淋洗柱子,用5%(体积分数)硝酸溶液以1 mL·min^(-1)速率洗脱柱子,收集10 mL洗脱液,在检测波长214.439,257.610,231.604,206.200,327.395,220.353 nm处测定其中镉、锰、镍、锌、铜、铅含量。结果显示:目标元素标准曲线的线性范围为0.1~10.0 mg·L^(-1),检出限(3s)为4.0×10^(-4)~3.0×10^(-2)mg·L^(-1)。对含氯化钠废水、含氯化铵废水、含氯化钠和氯化铵的废水进行加标回收试验,目标元素的检出量在1.600 mg·L^(-1)以下,回收率为92.2%~102%,测定值的相对标准偏差(n=9)为0.50%~3.5%。

The target elements in high chloride and high salt wastewater as Cu,Pb,Zn,Ni,Cd and Mn were extracted with Chelex 100 resin in the optimized solid phase extraction(SPE)conditions with ICP-MS,and determined by ICP-AES.The samples of high chloride and high salt wastewater were digested by nitric acid and the solution was made up with acetate buffer solution(pH 6.5).The solid phase extraction column pre-filled with Chelex resin was activated with 0.5 mol·L^(-1)ammonium acetate solution,and after adding 10 mL of the sample solution at a rate of 1 mL·min^(-1),the column was rinsed with 0.5 mol·L^(-1)ammonium acetate solution and water.5%(volume fraction)nitric acid solution was used for elution of the column at a rate of 1 mL·min^(-1),and 10 mL of eluate was collected and analyzed for determination of the content of Cd,Mn,Ni,Zn,Cu and Pb at detection wavelengths of 214.439,257.610,231.604,206.200,327.395,220.353 nm.The results showed that linearity ranges of standard curves of the target elements were in the range of 0.1-10.0 mg·L^(-1),with detection limits ranged from 4.0×10^(-4)mg·L^(-1)to 3.0×10^(-2)mg·L^(-1).The spiked recovery tests were made on the 3 wastewater samples(containing NaCl,NH4 Cl and NaCl-NH4 Cl,respectively),and mass concentrations of the target elements were all less than 1.600 mg·L^(-1),giving recoveries in the range of 92.2%-102%,and RSDs(n=9)of the determined values in the range of 0.50%-3.5%.