顶空气相色谱法检测纸浆中羰基含量的研究

Determination of Carbonyl Groups of Pulp by Headspace Gas Chromatography

关键词:  顶空气相色谱  羰基基团  纸浆  硼氢化钠  氢气

Key Words:headspace gas chromatograph  carbonyl groups  pulp  sodium borohydride  hydrogen

摘要:研究了一种顶空气相色谱法检测纸浆中羰基含量的方法。该方法以一定量的NaBH₄与纸浆中的羰基基团在碱性介质(0.1 mol/L NaOH)中发生反应，样品瓶中未参与反应的NaBH₄在加入H₂SO₄后全部转化为H₂，以气相色谱中的热导检测器检测H₂含量，从而间接检测出纸浆中羰基基团的含量。该方法稳定、灵敏、精确，且重现性相对标准偏差小于1.0%，灵敏度检测最低定量检测限为1.26 μmol，回收率范围为97%~105%。

Abstract:A headspace gas chromatographic (HS-GC) method has been developed for the determination of carbonyl groups in pulp. The method is based on the reaction between sodium borohydride and carbonyl groups of pulp at an alkaline medium (0.1 mol/L NaOH), and the excess sodium borohydride is quantitatively converted to hydrogen after the solution is acidified by sulfuric acid. The released hydrogen is then determined by GC equipped with a thermal conductivity detector. Thus, the carbonyl groups of pulp can be indirectly quantified. The relative standard deviations in the reproducibility test are within 1.0%, and a sensitivity whose limit of quantification (LOQ) is 1.26 μmol, and a demonstrated recovery ranging from 97% to 105%. The present method is simple, rapid, and practical.