离子液体溶剂浮选-光度法测定环境水样中痕量铜

以等体积的离子液体1 丁基 3 甲基咪唑六氟磷酸盐（［Bmim］PF6）和乙酸乙酯的混合物为浮选剂，以四环素（TC）为捕集剂，建立了离子液体气浮溶剂浮选 光度法检测环境水样中痕量Cu的新方法。研究了溶液的pH值、络合物的组成、气体流速、浮选时间、干扰离子等因素的影响，确定了反应的最佳条件：在pH 58的溶液中，气体流速为50 mL/min，浮选时间为50 min时，Cu的富集倍数（α）达到98（500 mL初始样品/5 mL测定液），方法的表观摩尔吸光系数ε373为2.54×105 L·mol-1·cm-1,线性范围为0.08～0.56 mg/L，检出限为0.3 μg/L。实测了环境水样中Cu，相对标准偏差小于4.5%。该方法测定结果与原子吸收光谱法基本一致，适合于环境水样中痕量/超痕量Cu的分析。

Determination of trace copper(Ⅱ)in environmental water samples by spectrophotometry after solvent flotation with ionic liquid

The ionic liquid (1 butyl 3 methylimidazolium hexafluorophosphate, ［Bmim］PF6) was mixed with ethyl acetate in the same volume and used as flotation agent. A new determination method of trace Cu in environmental water samples by spectrophotometry after ionic liquid solvent sublation was established using tetracycline (TC) as trapping agent. The effect of pH, the composition of complex, the flow rate of gas, the flotation time and the interference ions was investigated to obtain the optimal reaction conditions. In the solution at pH 58, when the flow rate of gas was 50 mL/min and the flotation time was 50 min, the enrichment factor (α)of Cu was up to 98 (500 mL of original sample solution / 5 mL of testing solution). The apparent molar absorptivity ε373was 2.54×105 L·mol-1·cm-1, the linear range was 0.08~0.56 mg/L, and the detection limit was 0.3 μg/LThis method was applied to the determination of Cu in environmental water samples, and the relative standard deviation (RSD) was smaller than 4.5 %The determination results were basically consistent with those obtained by atomic absorption spectrometryThis method was applicable for the analysis of trace / super trace Cu in environmental water samples.