Browsing by Author "Ilmarinen, Jenni"

Sizing agents are chemical additives used in paper and board making to improve hydrophobicity and to control the water penetration into the fiber network. This thesis reviews various analytical methods that have been reported to analyze three sizing agents: alkyl ketene dimer (AKD), alkenyl succinic anhydride (ASA), and rosin. Overview of the analytical methods includes gas chromatography, high-performance liquid chromatography, and Fourier transform infrared spectroscopy, along with newer techniques like ultraviolet-visible absorption spectroscopy and near infrared spectroscopy. These agents are analyzed from various paper products, like paper, process waters and dispersion. While the goal is to retain all added sizing agents within the paper or board, complete retention is not achievable, and some agents are present in process waters. Analyzing sizing agent levels in process waters allows for the evaluation of sizing agent retention. In the experimental section, Kemira Oyj's AKD analysis method for process waters from paper mills is updated. The hazardous and possibly carcinogenic extraction Solvent A is replaced with the greener and safer Solvent B. Sample preparation is improved, reducing analysis time from six hours to one. Additionally, a new high performance liquid chromatography – evaporative light scattering detector (HPLC-ELSD) method is introduced, capable of simultaneously analyzing AKD and hydrolyzed AKD (HAKD) in a single chromatogram. This is the first time a HPLC method is reported for analyzing HAKD from process waters. This method achieves 99% recovery rates with 0.2 ppm LOQ for both AKD and HAKD.