A novel method to quantify chitosan in aqueous solutions by ultrahigh-performance liquid chromatography–tandem mass spectrometry

In this study, a novel and accurate quantitative analysis method for the direct determination of chitosan (CS) in aqueous solutions using ultrahigh-performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) is presented. By detecting the mass spectrum response intensity of a series of CS characteristic ion pairs , the sample concentration (abscissa) was linearly fitted with the total ion current (TIC) response intensity of its characteristic ion pairs (ordinate). A reliable standard curve was derived for quantifying CS in the range of 125–4000 ng/mL. Under the detection conditions, this CS quantification method yielded acceptable specificity (no interference peak), linearity (with correlation coefficient (r 2 ) values >0.999), precision (acceptable limit RSD r  < 3 %, RSD R  < 6 %), accuracy (RE within the acceptable limits of ±5 %), and stability (acceptable limit RE within ±5 %, RSD r  < 3 %). Moreover, the applicability of measurement was verified when a series of substrates did not interact with CS in the solution. Results have verified the applicability of this method for determining CS content in different composites. This study provides a method for determining CS content with significant practical value and economic benefit.