流动注射在线萃取色谱预浓集火焰原子吸收法测定钯

Flow Injection On-line Extraction Chromatography Separation and Preconcentration System for Determination of Trace Palladium by Flame Atomic Absorption Spectrometry

以三异辛胺萃淋树脂为微型柱固定相 ,采用流动注射在线预浓集与火焰原子吸收法联用技术 ,对微量钯的测定进行了研究。在 0 .5mol L的HCl介质中以 7.8mL min的速率采样 90s再用 0 .1mol L硫脲 0 .5mol LHCl洗脱 ;在 2 7h- 1 的采样频率下 ,浓集系数为 5 0倍 ,浓集效率为 2 2 .5min ,消耗指数 0 .2 3mL。线性范围为 0～ 10 0 0 μg L ,检出限为 0 .34μg L。钯含量水平 5 0 μg L时 ,连续 11次测定的相对标准偏差为 2 .6 % ,并对加氢催化剂中的钯进行了加标回收率实验 ,回收率为 99.3%～ 10 1.2 %。

A flow injection on-line extraction chromatographic separation and preconcentration system is proposed for the determination of trace palladium by flame atomic absorption spectrometry (FAAS). The micro-column used was packed with tri-iso-octylamine levextrel resin, which was-synthesized by the authors as stationary phase. Sample in 0.5 mol/L HCl was pumped through a micro-column at the rate of 7.8 ml/min. In 90 s sampling time-and 1 45 s elution time, palladium was absorbed and then eluted into the nebulizer of FAAS by 0.5 mol/L HCl-0.1 mol/L thiourea solution. At the sampling frequency of 27/h, an enrichment factor of 50, concentration efficiency of 22.5/min and consumptive index of 0.23 mL were obtained. The linear calibration range was 0 similar to 1006 mug/L. The detection limit (3sigma) was 0.34 mug/L. The relative standard deviation at the 50 mug/L levels was 2.6% (n=11). The proposed method hash been applied to the catalyst sample analysis. The recovery of palladium was 99.3% similar to 101.2%.