负载PAN-S强碱性阴离子交换纤维富集-GFAAS法测定海水中的痕量镉

PAN-S loaded strong alkaline anion exchange fiber enrichment-GFAAS for the determination of trace Cd in seawater

为了消除石墨炉原子吸收法测定海水中痕量镉所存在的基体效应,采用负载PAN-S强碱性阴离子交换纤维柱吸附海水中的Cd2+实现与海水基体的分离,最后以HNO3附的Cd2+供测定。在p H5时,1000 m L海水样品中的Cd2+离子,可在过柱液流速小于14 m L/min下定量富集在填充有0.5g离子交换纤维的固相萃取柱上,并可被10 m L 0.1 mol/L HNO3完全洗脱。洗脱液中共存离子含量分别为Ca2+(0.034 mg),K+(0.045 mg),Mg2+(0.045 mg),Na+(0.107mg),Ba2+(17.1μg),Al3+(0.586μg)时,对测定无影响。镉的方法检出限为0.008μg/L。用该方法富集和测定了国家标准物质GBW(E)080040和NASS-6中的镉,结果均与标准值吻合。

In order to eliminate the matrix effect on determination of trace cadmium in seawater using GFAAS,cadmium was adsorbed by PAN-S loaded strong alkaline anion exchange fiber from seawater,and eluted with HNO3 for GFAAS analysis. The results showed that Cd2 ＋in 1000 m L seawater sample can be quantitatively concentrated on 0. 5 g PAN-S loaded strong alkaline anion exchange fiber packed in a SPE column with a flow rate of 14 m L / min,and then completely eluted from the column by 10 m L 0. 1mol / L HNO3. The contents of coexisting ions in eluent were Ca2 ＋（ 0. 034 mg）,K＋（ 0. 045 mg）,Mg2 ＋（ 0. 045 mg）,Na＋（ 0. 107 mg）,Ba2 ＋（ 17. 1 μg）,Al3 ＋（ 0. 586 μg）,which had no effect on the determination. The detection limit was 0. 008 μg /L for cadmium. The proposed method was validated by the analysis of GBW（ E） 080040 and NASS-6 seawater certified reference materials.