Tu Zhifeng, He Qun, Chang Xijun, Hu Zheng, Gao Ru, Zhang Lina, Li Zhenhua
Department of Chemistry, Lanzhou University, Lanzhou 730000, PR China.
Anal Chim Acta. 2009 Sep 7;649(2):252-7. doi: 10.1016/j.aca.2009.07.042. Epub 2009 Jul 21.
A novel method that utilizes 1-(2-formamidoethyl)-3-phenylurea-modified activated carbon (AC-1-(2-formamidoethyl)-3-phenylurea) as a solid-phase extractant has been developed for simultaneous preconcentration of trace Cr(III), Cu(II), Fe(III) and Pb(II) prior to the measurement by inductively coupled plasma atomic emission spectrometry (ICP-AES). Experimental conditions for effective adsorption of trace levels of Cr(III), Cu(II), Fe(III) and Pb(II) were optimized using batch and column procedures in detail. The optimum pH value for the separation of metal ions simultaneously on the new sorbent was 4. And the adsorbed metal ions could be completely eluted by using 2.0 mL 2.0 mol L(-1) HCl solution. Common coexisting ions did not interfere with the separation and determination of target metal ions. The maximum static adsorption capacity of the sorbent at optimum conditions was found to be 39.8, 39.9, 77.8 and 17.3 mg g(-1) for Cr(III), Cu(II), Fe(III) and Pb(II), respectively. The detection limits of the method were found to be 0.15, 0.41, 0.27 and 0.36 ng mL(-1) for Cr(III), Cu(II), Fe(III) and Pb(II), respectively. The relative standard deviation (RSD) of the method was lower than 4.0% (n=8). The method was successfully applied for the preconcentration of trace Cr(III), Cu(II), Fe(III) and Pb(II) in natural and certified samples with satisfactory results.
已开发出一种新方法，该方法利用1-(2-甲酰胺基乙基)-3-苯基脲修饰的活性炭（AC-1-(2-甲酰胺基乙基)-3-苯基脲）作为固相萃取剂，用于在电感耦合等离子体原子发射光谱法（ICP-AES）测量之前同时预富集痕量Cr(III)、Cu(II)、Fe(III)和Pb(II)。使用分批和柱操作程序详细优化了有效吸附痕量Cr(III)、Cu(II)、Fe(III)和Pb(II)的实验条件。在这种新型吸附剂上同时分离金属离子的最佳pH值为4。吸附的金属离子可用2.0 mL 2.0 mol L(-1) HCl溶液完全洗脱。常见共存离子不干扰目标金属离子的分离和测定。在最佳条件下，该吸附剂对Cr(III)、Cu(II)、Fe(III)和Pb(II)的最大静态吸附容量分别为39.8、39.9、77.8和17.3 mg g(-1)。该方法对Cr(III)、Cu(II)、Fe(III)和Pb(II)的检测限分别为0.15、0.41、0.27和0.36 ng mL(-1)。该方法的相对标准偏差（RSD）低于4.0%（n = 8）。该方法成功应用于天然样品和标准样品中痕量Cr(III)、Cu(II)、Fe(III)和Pb(II)的预富集，结果令人满意。
