Determination of sugar content in honey using LC-Raman and programmable pump-Raman methods

We combined (i) liquid chromatography and Raman spectrometry (LC-Raman) and (ii) programmable pump and Raman spectrometry (PP-Raman) to separate and identify compounds in a mixture. These techniques were applied to conduct a quantitative analysis of the sugars in honey. The spectral and temporal axes of the LC-Raman data were analyzed using the MCR-ALS analysis procedure, which enabled the separation and identification of four sugars (glucose, fructose, sucrose, and trehalose). The PP-Raman method was employed to examine the sugar concentration dependence of the intensity pattern of the Raman spectrum, and the linear concentration dependence of the intensity was obtained. The sugar contents were quantitatively determined from the integrated area of the elution peaks. The result was consistent with those derived from mass spectrometry and previous studies. The origin of the errors in the derived sugar contents is discussed. Our study presents a novel quantitative LC-Raman spectrometric method that does not rely on resonance or surface enhancement effects.

Automated summary

In this study, a combination of liquid chromatography-Raman spectroscopy (LC-Raman) and programmable pump-Raman spectroscopy (PP-Raman) was used to separate and identify compounds in a mixture. These techniques were used for quantitative analysis of sugars in honey. The LC-Raman data was analyzed using the MCR-ALS analysis procedure to separate and identify four sugars, while the PP-Raman method examined the concentration dependence of the Raman spectrum intensity. The sugar contents were quantitatively determined and compared with mass spectrometry and previous studies.