Direct determination of cationic starches in paper samples using analytical pyrolysis

•Improvement of the direct quantification with analytical pyrolysis.•Optimization of the chromatographic parameters after pyrolysis of cationic starch.•Quantification of cationic starches in cellulose matrixes.•Validation of the cationic starch quantification in paper samples.

The current work presents a method for direct detection and quantification of cationic starch in paper samples. Based on analytical pyrolysis gas chromatography–mass spectrometry (Py-GC/MS), the method allows for simplified sample preparation. Furthermore, the proposed method assesses the amount of cationic starch in the presence of other starches. The cationic starch concentration in paper is calculated using a pyrolysis product from the cationic group. Therefore, the results of the described method are unbiased in the presence of other starch modifications. Validation characteristics of the method, such as standard error of calibration, limit of determination, linearity and accuracy, are reported. To demonstrate the accuracy of the novel method, a comparison against the existing reference quantification method, SCAN-P 91:09, from the Scandinavian Pulp, Paper and Board Testing Committee was performed.