Li Zhenhua, Chang Xijun, Hu Zheng, Huang Xinping, Zou Xiaojun, Wu Qiong, Nie Rong
Department of Chemistry, Lanzhou University, Lanzhou 730000, PR China.
J Hazard Mater. 2009 Jul 15;166(1):133-7. doi: 10.1016/j.jhazmat.2008.11.006. Epub 2008 Nov 13.
A new method that utilizes zincon-modified activated carbon (AC-ZCN) as a solid-phase extractant has been developed for simultaneous preconcentration of trace Cr(III) and Pb(II) prior to the measurement by inductively coupled plasma optical emission spectrometry (ICP-OES). The separation/preconcentration conditions of analytes were investigated, including effects of pH, the shaking time, the sample flow rate and volume, the elution condition and the interfering ions. At pH 4, the maximum adsorption capacity of Cr(III) and Pb(II) onto the AC-ZCN were 17.9 and 26.7 mg g(-1), respectively. The adsorbed metal ions were quantitatively eluted by 1 mL of 0.1 mol L(-1) HCl. Common coexisting ions did not interfere with the separation. According to the definition of IUPAC, the detection limits (3 sigma) of this method for Cr(III) and Pb(II) were 0.91 and 0.65 ng mL(-1), respectively. The relative standard deviation under optimum condition is less than 3.5% (n=8). The method has been applied for the determination of Cr(III) and Pb(II) in biological materials and water samples with satisfactory results.
一种利用锌试剂改性活性炭（AC-ZCN）作为固相萃取剂的新方法已被开发出来，用于在电感耦合等离子体发射光谱法（ICP-OES）测定之前同时预富集痕量Cr(III)和Pb(II)。研究了分析物的分离/预富集条件，包括pH值、振荡时间、样品流速和体积、洗脱条件以及干扰离子的影响。在pH 4时，Cr(III)和Pb(II)在AC-ZCN上的最大吸附容量分别为17.9和26.7 mg g(-1)。吸附的金属离子用1 mL 0.1 mol L(-1) HCl定量洗脱。常见的共存离子不干扰分离。根据国际纯粹与应用化学联合会（IUPAC）的定义，该方法对Cr(III)和Pb(II)的检测限（3σ）分别为0.91和0.65 ng mL(-1)。在最佳条件下相对标准偏差小于3.5%（n = 8）。该方法已应用于生物材料和水样中Cr(III)和Pb(II)的测定，结果令人满意。
