|Abstract Title:||Application of tandem UV/Charged aerosol detection in analysis of bioactive substances in food supplements|
|Presenter Name:||Mr Jakub Fibigr|
|Co-authors:||Ms Ivona Lhotská|
Dr Dalibor Šatínský
|Company/Organisation:||Charles University, Faculty of Pharmacy|
Abstract Information :
Detection of any nonvolatile or semivolatile analyte without a chromophore or a fluorophore in its molecule, gradient compatibility and very good sensitivity are main advantages of the universal evaporative Corona-charged aerosol detector (CAD). This type of detector is very suitable alternative to routinely used UV (PDA) detector for UHPLC analysis of biologically active substances with low or no response in UV spectrum contained in food supplements, such as plant sterols, stanols, and steviol glycosides.
Phytosterols and their esters are natural steroids that are important structural components of plant membranes. Most phytosterols contain 28 or 29 carbons and one or two carbon-carbon double bonds. Phytostanols are a fully-saturated subgroup of phytosterols (contain no double bonds). In addition to the free form, both phytosterols and phytostanols occur as conjugates in which the 3 -OH group is esterified to a fatty acid.
Steviol glycosides are a group of diterpene glycosides used as natural sweeteners. Usually, the total content of steviol diterpenoids is composed of stevioside, rebaudioside A, rebaudioside C and dulcoside A. Minor components are rebaudioside D, E and F.
In our study, it was proved that sensitivity of CAD is approximately three-times better than UV under 210 nm, and that CAD is capable of a detection of compounds not detectable in the UV spectrum. The developed method provided a faster analysis with higher sensitivity, the separation of more compounds and a wider calibration range than earlier described meth-ods employing evaporative detectors (ELSD). In the most GC methods (except that with MS detection) which are commonly used for analysis of phytosterols a derivatization of free ster-ols after saponification had to be done prior to the analyses. With the use of CAD, no derivat-ization is needed, which saves the labor-time and yield of the extraction.