离子缔合三元络合物的溶剂浮选分离富集—原子吸收光谱法测定矿石中微量金

Determination of Microamount Gold in the Ore by Solvent Flotation on the Tri-ion Associate Complex of Gold-Atomic Absorption Spectrophoto- metry(AAS)

在合适的酸度和试剂下,Au^(8+)与电负性配位体R^-(I^-、Br^-、SCN^-)形成络阴离子(AuR_4^-),然后与碱性染料BH^+(MB^+、MV^+、RB^+)生成离子缔合三元络合物(离子缔合物AuR_4^-·BH^+),用浮选剂甲苯从水相中浮选分离富集微量金的离子缔合物于水相—有机相两相界面呈第三相沉淀。浮选物[RH^+·AuR_4^-]溶于DMF,直接雾化此溶液,以空气—乙炔焰原子吸收法测定。研究了AuI_4·MV、AuI_4·MB、AuBr_4·RB和AuSCN_4·RB四个浮选体系的浮选工作条件和行为。试验表明,本法富集倍数大,灵敏度高,选择性好,适用于测定矿石和海水中微量金,简便快速,结果满意。

A sensitive, precise and selective method for the determination of microamount gold in ore, based on the ion associate of the ion Au3+, I-, Br- or SCN- complex with methylene blue (MB), let(MV) or rhodamine (RB ) , has been developedo The ion associate is flotmethyl vioated with methyl benzene and dissolved in dimethyformamide ( DMF ) , and its determination is carried out by AAS. The formation of the ion associate takes place over pH range 1.0-5.0 (for Au-I-MB) , 1.0-6.0 (for Au-I-MV), 0.5-2.5( for Au-SCN-RB ) , 0.70-1.5 (for Au-Br-RB ) . The analytical results obtained for Au in ore are in good . agreement wtih the standard values.