样品预处理结合红外光谱分析鉴定纸张中的硫酸钡

A New Sample Pretreatment Method of Infrared Spectrum Analysis for Barium Sulfate Identification in Paper

关键词:  纸张  硫酸钡  酸洗  红外光谱法

Key Words:paper  barium sulfate  pickling  infrared spectrum

摘要:纸张中加入少量硫酸钡是为了起到防伪作用，但由于纸张本身所含有机基体、碳酸钙及高岭土所产生的干扰，对于纸张中的硫酸钡分析鉴定非常困难。本实验探讨了上述干扰因素对现行国家标准方法(GB/T2679.12—1993)的影响,建立了一种样品预处理结合红外光谱分析鉴定纸张中少量硫酸钡的新方法。本方法基于国家标准方法进行样品灰化处理,然后采用1 mol/L的盐酸标准溶液对灰分残余物进行多次酸洗,依次排除有机物和碳酸钙的干扰。结果表明，该方法可以克服现行国家标准方法的缺陷,提高了红外光谱检测硫酸钡的灵敏性,适用于纸张中少量硫酸钡的定性分析。

Abstract:This paper discussed the effect of the interference caused by the organic matrix, calcium carbonate and kaolin on the standard method (GB/T 2679.12—1993) for identification of Barium Sulfate in paper by infrared spectrum, and proposed a new method based on novel sample pretreatment together with infrared spectrum analysis. On the basis of the national standard method, the sample was calcined to be ash, and then the ash was leached with 1 mol/L hydrochloric acid to eliminate the interference of organic material and calcium carbonate. The results showed that the proposed method could efficiently overcome the shortcomings of the national standard method, and improve the detection sensitivity of infrared analysis is suitable for qualitative determination of trace barium sulfate content in paper.