树状聚酰胺胺-水杨醛修饰硅胶分离富集镉

Preconcentration and separation of cadmium with dendrimer-like polyamidoamiene and salicylaldehyde modified silica-gel

制备了树状聚酰胺胺-水杨醛修饰硅胶PAMAM-n.0SASG(n=1,2,3,4),利用FTIR,SEM,元素分析对其进行表征。研究了PAMAM-n.0SASG微柱分离富集Cd(Ⅱ)的性能。结果表明,在pH 7的HCl介质溶液中,以3.0 mL/min流速进样,可以实现Cd(Ⅱ)定量吸附。PAMAM-n.0SASG对Cd(Ⅱ)的吸附容量分别为11.12,17.79,24.46和37.79 mg/g(n=1,2,3,4),富集倍数分别达到100,150,200,300倍。准二级动力学方程可以较好的描述PAMAMn.0SASG对Cd(Ⅱ)的吸附行为,使用100个吸附和解吸附循环后,其吸附性能未发生变化。以PAMAM-4.0SASG为吸附剂建立了微柱分离富集-石墨炉原子吸收光谱测定Cd(Ⅱ)方法,检出限达到0.9 ng/mL,测定Cd(Ⅱ)的线性范围是2.0~20 ng/mL。方法已应用于标准样品和水样中Cd(Ⅱ)分析。

Dendrimer-like polyamidoamine and salicylaldehyde were linked to silica-gel surface to obtain novel adsorbents PAMAM-n. 0SASG （n = 1,2,3,4）. After characterized with FTIR, SEM, elemental analysis, PAMAM-n. 0SASG was used as packing for micro-column adsorption of Cd （ Ⅱ ）. The experiment results showed that Cd（ Ⅱ ） in pH 7.0 HCl solution could be quantitatively absorbed with a sampling flow rate of 3.0 mL/min. Adsorption capacity of PAMAM-n. 0SASG （n = 1,2,3,4 ） for Cd（ Ⅱ ） was 11.12, 17.79, 24.46 and 37.79 mg/g respectively. Preconcentration factor （PF） of PAMAM-n. 0SASG （ n = 1,2,3,4） for Cd （ Ⅱ ） reached 100, 150, 200 and 300 respectively. PAMAM-n. 0SASG （n = 1,2,3,4） could be used no less than 100 cycles without change of adsorption property. Pseudo-seond-order model was more suitable to interpret the kinetics of adsorption of Cd（ Ⅱ）. With PAMAM -4. 0SASG as adsorbent, Micro-column preconcentration-graphite furnace atomic absorption spectrometry （GFAAS） method for analysis of Cd （ Ⅱ） was proposed. The limit of detection （LOD） for Cd（ Ⅱ ） was 0.9 ng/mL. The linear range for the determination of Cd（ Ⅱ ） was 2 -20 ng/mL. The proposed method was successfully applied to the analysis of Cd （ Ⅱ ） in standard reference material and sea water.