Abstract:

A method to measure the contents of glyceoyl and acetyl in gellan with high performance liquid chromatography
(HPLC) was established. Acyl groups were dissociated from gellan by hydrolization and acidized to obtain acetic acid and
glyceric acid. Then alcohol precipitation was used to remove the gel and the contents of the two kinds of organic acids
were assayed by HPLC. The contents of the two acyl groups were calculated according to the corresponding relationship in
molecular weight between the acyl groups and organic acids, using propionic acid as the internal standard substance. The
chromatographic column used was HPX-87H with 5 mmol/L sufuric acid as the mobile phase at a flow rate of 0.6 mL/min.
The column temperature was maintained at 35 ℃, and the analytes were detected at a UV wavelength of 210 nm. The
method could quantify these two organic acids simultaneously within 20 min. It is an efficient method with excellent
repeatability and stability. The contents of glyceroyl and acetyl of gellan produced in our laboratory were 9.94% and 3.29%
with spiked recoveries of 97.76% and 93.49%, respectively.

Key words: high performance liquid chromatography (HPLC), gellan, acetyl, glyceroyl