Analysis of the State of Dissolved Water in Methyldecanoate and Safflower Oil by FT-Near Infrared Spectrometry

The characteristic absorption bonds of free water, structural water and unsymmetrically hydrogen bonded water were recorded in the range from 5, 040 to 5, 360cm-1 for dissolved water in methyldecanoate (172, 455ppm) and safflower oil (301, 780ppm). The sum of the intensities of three characteristic absorption bonds increased in proportion to the amount of dissolved water determined by the Karl Fisher method in methyldecanoate and safflower oil. Each intensity increased in proportion to the amount of dissolved water in the range from 364 to 2, 455ppm in methyldecanoate and from 30 to 1, 780ppm in safflower oil. In methyldecanoate the dissolved water was almost in the form of unsymmetrically hydrogen bonded water from 17 to 53ppm, but was 67% structural water at 176ppm. In the case of safflower oil, the dissolved water from 30 to 64ppm contained about 10% of the unsymmetrically hydrogen bonded water. These findings may be explained on the basis of the steric hindrance of the molecular structure.