界面活性剤分析法の研究 (第32報)
近赤外吸収スペクトルによる洗剤中の水分の定量
1974 年 23 巻 2 号 p. 109-113
詳細
1974 年 23 巻 2 号 p. 109-113
A rapid method for the determination of moisture in liquid and granulated detergents by nearinfrared spectroscopy was established.
Using DMF as the solvent, water has strong absorption at 1.93μ in the near-infrared region. The linear relationship is obtained between the absorbance value at 1.93μ and water content. Further, water in detergent is dissolved or extracted readily by DMF.
Based on these facts, in this method, detergent sample (containing 0.20.3g of the water) was weighed into 50ml volumemetric flask, DMF was added until marked line, and the flask was shaken. The spectrum of the solution was mesured from 1.7μ to 2.2μ in 1cm silica cell. And the absorbance value was obtained from peak-height of the band at 1.93μ by the baseline method. The moisture content was obtained from the absorbance value and the calibration curve.
By this method, the moisture content in liquid and granulated detergent can be determination with a standard diviation of 0.94% as contrasted to Karl Fischer method.
