纳米碳纤维分离富集电感耦合等离子体质谱法测定地质样品中痕量Au

Determination of Gold in Geological Sample by Inductively Coupled Plasma Mass Spectrometry after Carbon Nanofibers Separation and Preconcentration

提出了纳米碳纤维微柱分离富集电感耦合等离子体质谱法(ICP-MS)测定地质样品中痕量Au的方法。考察了在动态条件下纳米碳纤维对Au3+的吸附行为,并确定了最佳吸附及洗脱条件。实验结果表明:在pH2时,待测物可被纳米碳纤维定量富集,用pH1的3%硫脲溶液可将吸附在纳米碳纤维上的Au3+定量洗脱。方法对Au的检出限为0.16ng.mL-1,精密度(RSD)为8.5%(n=6),用于测定实际样品中痕量Au的含量,所得结果与标准值吻合较好。

A novel method for the determination of Au by inductively coupled plasma mass spectrometry （ICP-MS） is described. Au can be separated and preconcentrated with a micro-column packed with carbon nanofibers as an adsorption material. The adsorption and elution behaviors of Au^3＋ on carbon nanofibers were systematically investigated under dynamic conditions. The experimental results showed that the studied ions can be adsorbed quantitatively at pH 2. 0, and the analytes adsorbed on the column can be eluted with H2NCSNH2-HCl solution at pH 1.0. Under the optimum conditions, the detection limits for Au is 0. 15 ng·mL^-1, and the relative standard deviation （RSD） is 8. 5% （n=6）. The proposed method has been applied to the determination of trace Au in geological standard material with satisfactory results.