矿石中金的在线固相萃取及缝管火焰原子吸收测定

Determination of Gold in Ores by Atomic AbsorptionSpectrometry Using Slotted Quartz Tube Combined with FI On-Line Solid Phase Extraction

介绍了将流动注射在线固相萃取预浓集与石英缝管火焰原子吸收相结合测定矿石中金的方法。用ＸＡＤ８吸附树脂填充的微型柱（１００μｌ）在６ｍｌ／ｍｉｎ的流速下，从０．５ｍｏｌ／ＬＨＣｌ介质的试样溶液中浓集金氯络合物，再用乙醇洗脱，最后由火焰原子吸收检测。在采样频率为１０３样／ｈ的流速下灵敏度提高４７倍，分析精度（ＲＳＤ）为１．３％（０．１μｇ／ｍｌＡｕ，ｎ＝１１），检出限为１．０μｇ／Ｌ（３σ）；在６５样／ｈ的采样频率下灵敏度提高９５倍，检出限可达０．６μｇ／Ｌ，对于矿石的检出限为０．０１５ｇ／ｔ，矿样消化液中加金的回收率为９１％～１０６％。

I on-line solid phase extraction is combined with flame atomic absorption spectrometry using a slotted quartz tube,The microcolumn packed with XAD-8 resin(l00μl) was used to concentrate Au-Cl complexes from samples in0.5mol/L HCl at 6ml/min for 20s,ethanol was usedto elute the analyte. An enhancement factor of 47 was obtained at a sampling frequency of 103/h with a precision of 1.3%RSD(0.1μg/ml level,n=11).The detection limit was 0.6μg/L(3σ),corresponding to 0.015g/t Au in ores.Recoveries obtained by spiking ore digests with gold standard solution were 91%～106%.