The HPLC Determination of Salicin and Polyphenolic ... - Shimadzu

Figure 1: Simultaneous PDA (UV 210, 268nm) and ELSD-LT chromatograms obtained for
commercial White Willow bark extract.
Results and Conclusion
Salicin shows two absorbance maxima in the UV, 210 and 268nm. Figure 1 shows a
comparison of the chromatographic profiles of ELSD with those two wavelengths. Here, the
ELSD-LT reveals a number of non-chromophoric constituents eluting later than the salicin.
Based upon their retention mechanism with this column chemistry, akin to a saccharide series,
these are presumably polyphenolic glucosides [2] .
While salicin may be determined using either detector, the myriad of salix constituents
are revealed by the evaporative light scattering detector alone. As illustrated by the data, a
compromise would be appropriate to balance the detector selectivity and sensitivity with
baseline response when using a UV detector. This is a common situation. Conversely, the
ELSD is immune to changes in solvent bulk properties and also yields better sensitivity toward
the constituent chemicals of salix alba.
SSI-HPLC -AN-002