壳聚糖在线微柱预富集火焰原子吸收光谱法测定矿石中的痕量金

Flame Atomic Absorption Spectrometric Determination of Trace Gold with Flow Injection On-line Preconcentration on Microcolumn Packed with Chitosan

报道了壳聚糖作在线微柱预富集填料,流动注射与火焰原子吸收光谱联用(FI-FAAS)测定痕量金的方法。将金与硫氰酸钾混合富集在壳聚糖上并以硫脲作洗脱剂。当采样体积10.3 mL时,采样频率36个样/h,富集倍数26倍。检出限(3σ,n=11)0.50μg.L-1,相对标准偏差1.4%(ρAu=0.10 mg/L)和2.4%(ρAu=0.01mg/L)。该方法用于矿石中金的测定,结果满意。并探讨了壳聚糖吸附金的机理。

A new method for the determination of trace gold by flow injection on-line preconcentration on a microcolumn packed with chitosan coupled with flame atomic absorption spectrometry was established.Gold was mixed on-line with KSCN and preconcentrated on chitosan.Thiourea was used as eluent.The preconcentration factor was found to be 26 at a sample volume of 10.3 mL and sampling frequency of 36 h-1.The linear range was 0.0050.5 mg·L-1 with a detection limit of 0.50 μg/L（3σ,n=11）.The RSD obtained by testing at concentration level of 0.10 and 0.01 mg/L for 11 times were 1.4% and 2.4%,respectively.Satisfactory results were obtained for the determination of trace gold in ore samples.The mechanism of the adsorption of gold on chitosan was discussed.