Determination of isotope abundance for deuterium-labeled compounds by quantitative 1 H NMR + 2 H NMR.

Deuterated reagents have been used in many research fields. Isotope abundance, as the feature parameter of deuterated reagents, the precise quantification, is of great importance. Based on quantitative nuclear magnetic resonance technology, a novel method that combines 1 H NMR + 2 H NMR was systematically established to determine the isotopic abundance of deuterated reagents. The results showed that the isotopic abundance of partially labeled and fully labeled compounds calculated by this new method was even more accurate than that calculated by classical 1 H NMR and mass spectrometry (MS) methods. In brief, this new method is a robust strategy for the determination of isotope abundance in large-scale deuterated reagents.

[Regularity of effective carbon numbers of alkanes, alcohols and ethers and its application to determination without authentic standards by gas chromatography].

To realize quantitative analysis without authentic standards by gas chromatography, a calculation method of effective carbon numbers (ECNs) was developed by determining the relative response factors of 66 alkanes, alcohols, ethers with GC-FID and studying the relation between ECNs and chemical structures. The correlation coefficient of 0.9998 (N=66) was achieved between theoretical values and experimental values of ECNs. Fifty-seven percent of determined compounds had relative deviations within ±1% and all of them had relative deviations within ±3%. This method is as accurate as common internal-standard method while used in the determination of oxygenated chemicals in gasoline samples, but with far less time and economical cost. It could be used to solve the problem of lacking authentic standards or surrogates.