An accurate and robust multicomponent quantitative analysis method: Molar mass coefficient method.

Abstract

Multicomponent quantitative analysis (MCQA) is necessary for comprehensively characterizing the quality of complex samples, including medicines, foods. However, the limited supply of reference substances and the high costs associated with testing hinder the application of the MCQA using the external standard (ES) method. Here we propose a Molar Mass Coefficient (MMC) method for the quantification of multiple compounds with identical chromophore utilizing a single reference compound (SRC) by a UV detector. This method involves establishment of a linear equation of SRC (y_r=ax_r+b) with a standard compound r, followed by the derivation of quantitative equations for other components i using the deduced formula (y_i=(M_r/M_i)ax_i+b). The MMC method introduces only two known physical parameters, specifically the molar mass of compounds r and i, which ensures both the accuracy and practicality of this method. The feasibility of the MMC method was demonstrated with a set of simulated samples containing 17 flavonoids standard compounds, and further validated with samples of Scutellariae Radix and Ginkgo dry extract. The newly established method could accurately quantify flavonoids, yielding results and robustness consistent with the traditional ES method. Notably, for the contents of baicalin and kaempferol, when compared to the results obtained by ES method, the relative standard deviations (RSD%) for the commonly used method were 5.72 % and 4.96 %, respectively, while these values fall down to 0.73 % and 1.02 % when employing the MMC method. The MMC method exhibited significant advantages over existing methods, including high accuracy, robustness and low cost, implying its broad application in different fields.