¹³C-NMRスペクトルのコンピューター解析による混合物の組成分析

化粧品への応用

抄録

We have developed a new system designed for composition analysis of mixtures of organic compounds.
This system consists of the measurement of ¹³C-NMR (CMR) spectrum of an unknown sample (usually a mixture of manifold compounds) and of subsequent computer analysis of the spectrum. The analyses of CMR spectra are carried out on the basis of the standard spectra of authentic compounds which are already stored in floppy disks (data base).
The first step of the procedure is to search candidate compounds that are deemed to be present in the sample, The second step is the signal assignment, which is conducted accoding to multiple regression analysis, and the final step of simulation which is made so as to minimize the sum of the square of error (difference between the observed signal intensity and the calculated one) gives the relative composition of each component.
In the present study, we have applied this system to the composition analysis of cosmetic products such as lipsticks and creams, and the results demonstrated the usefulness of this new system for both qualitative and quantitative determination of various mixtures.
This system requires little or no separation process nor technical knowledge of the operator, and is also applicable to a variety of scientific fields other than cosmetic research. The system, however, is not suitable for the analysis of trace components or polymers because of the insufficient sensitivity of CMR spectroscopy.