A novel alginate quantification method using high-performance liquid chromatography (HPLC) for pretreatment of Saccharina japonica

Abstract

A new analysis method for alginate quantification in the brown alga, Saccharina japonica, was developed and evaluated. In this method, (1) alginate was treated with Na2CO3; (2) the alginate-derived compound in the hydrolysate was analyzed using high-performance liquid chromatography (HPLC); and then, (3) one of the HPLC peaks was selected and used to establish the standard calibration curve to estimate the intact alginate content in the raw material. The results obtained using the new method were verified by the Kennedy and Bradshaw method, which confirmed that the new method can be an effective method for the estimation of the alginate content in S. japonica. An experimental equation was developed to estimate the alginic acid concentration in the hydrolysate obtained from Na2CO3 treatment of the model compound (Sigma Na-alginate) at various reaction conditions on the basis of the correlation between estimated alginic acid contents and combined severity factors (CSF). The statistical analysis confirmed that the equation gave consistent results, i.e., approximately 81 % of the test groups lie within <+/- 10 % standard deviation of the mean.