利用铬黑T分光光度法快速测定硅酸盐中的铝

摘要

研究了Al3＋与铬黑T显色反应的影响因素，对硅酸盐试样中大量存在的钙的干扰，采用加入EGTA进行掩蔽。Al3＋量在0～0.8μg/mL内符合比耳定律，其表观摩尔吸光系数为2.1×10４，回归方程为A＝0.000*!74ρ(μg/mL)+0.06*!176，相关系数为γ＝0.981。可用于硅酸盐试样中微量铝的测定。%The factors of reaction between calcochrome black T and Aliminium were studied.The method of the spectrophotometric determination of trace aluminium is found.The mole absorptivity coefficient is 2.1×10４,and the Beer's law is obeyed in the 0～0.8μg/mL range of Al3＋ content.The regression equation of calibration graph is ΔΑ＝0.000*!74ρ(μg/mL)+0.061*!76,with a correlation coeffcient of 0.981.This method is able to be used in the determination of trace aliminium in silicate samples.