日本質量分析学会 第66回質量分析総合討論会

Program

Poster Presentations

Day 1, May 15(Tue.)  Poster

Analysis of carbon isotope ratios for compounds in honey by means of a liquid chromatography/isotope ratio mass spectrometry system coupled with a post-column pump

(Akita Pref. Univ.)
oMomoka Suto, Hiroto Kawashima, Nana Suto

In 2004, liquid chromatography coupled with isotope ratio mass spectrometry (LC/IRMS) has been developed, which allows the measurement of stable carbon isotope (δ13C) composition of highly polar and non-volatile analyses. However, LC/IRMS has several disadvantages, including the high cost of the CO2 membrane, the low total flow rate, etc. Here, we developed an improved system for determining carbon isotope ratios by LC/IRMS. Particularly, the column flow rate can be changed arbitrarily by the post column method. We applied the improved method to 26 commercial honey samples and one syrup sample to identify the authenticity of honey.
By LC/IRMS analysis, the δ13C values for glucose, fructose, disaccharides, trisaccharides, and organic acids ranged from –27.0 to –24.2‰, –26.8 to –24.0‰, –28.8 to –24.0‰, –27.8 to –22.8‰, and –30.6 to –27.4‰, respectively. In this study, we classified Δδ13C (fructose – glucose) values of >±1.0‰ or Δδ13C values of difference of each compound of > ± 3.0‰ as indicating adulteration. Using these authenticity criteria, we judged five samples to be adulterated. These results indicate that LC/IRMS is a powerful method for detecting adulterated honey.