【摘要】 建立了用交联羧甲基魔芋葡甘聚糖(CCMKGM)作为微柱预富集填料,分离富集-GFAAS测定环境水样中痕量铅、镉和铜的新方法。研究了溶液酸度、样品的流速和体积、洗脱剂的浓度和体积、共存离子等对CCMKGM微柱吸附重金属离子的影响。结果表明:在pH为5.0～7.0的条件下,三种重金属离子可定量吸附在CCMKGM微柱上;采用1.0mL0.5mol.L-1的盐酸溶液可将吸附在CCMKGM微柱上的铅、镉和铜定量洗脱。Pb2+,Cd2+,Cu2+的检出限(3σ)分别为0.038,0.0005和0.014μg.L-1,相对标准偏差(RSD)分别为3.5%,9.2%和4.7%(初始浓度cPb2+=cCu2+=1.0μg.L-1,cCd2+=0.1μg.L-1,n=11),富集倍数50。将该法用于环境标准样品的测定,测得值与标准值相符。更多还原

【Abstract】 A novel solid phase extraction technique was developed for the determination of trace lead,cadmium and copper in environmental water samples based on separation and preconcentration with a microcolumn packed with crosslinked carboxymethyl konjac glucomannan(CCMKGM)prior to its determination by graphite furnace atomic absorption spectrometry.Various influential factors on the separation and preconcentration of lead,cadmium and copper,such as the acidity of the aqueous solution,sample flow rate and volume,and eluent concentration and volume,were investigated systematically,and the optimized operation conditions were established.The analytes could be quantitatively retained by CCMKGM in the pH range of 5.0-7.0,then eluted completely with 1.0 mL 0.5 mol·L-1 HCl.The detection limits(3σ)for analyte ions were 0.038 μg·L-1 for Pb2+,0.000 5 μg·L-1 for Cd2+ and 0.014 μg·L-1 for Cu2+ with an enrichment factor of 50,and the relative standard deviations were 3.5% for Pb2+,9.2% for Cd2+ and 4.7% for Cu2+(cPb2+=cCu2+=1.0 μg·L-1;cCd2+=0.1 μg·L-1,n=11).The proposed method was successfully applied to the determination of trace lead,cadmium and copper in environmental water samples(local tap water and lake water).In order to validate the method,the developed method was applied to the determination of lead,cadmium and copper in environmental water reference materials(ERMs,GSBZ 50009-88,P.R.China),and the results obtained were in good agreement with the certified values.更多还原