Comparing different methods to determine moisture contents of heated tobacco materials based on correction results

To address the challenge in efficiently and accurately determining the moisture content of heated tobacco materials, accurate determination methods such as Karl Fischer, gas chromatography, and near-infrared spectroscopy were systematically compared and optimized. The mechanism of the effect of high doses of volatile substances on accuracy was investigated using glycerol as a representative. Based on this, a determination method and result correction models for the moisture content of heated tobacco material samples prepared by different production processes were established. The results showed that: 1) After optimizing the determination parameters, the spiked recoveries for Karl Fischer and gas chromatography methods were in the range of 99.50%-102.70% and 98.64%-108.70%, respectively. 2) To promote the efficiency of moisture content determination of heated tobacco materials during the production process, a polynomial moisture content correction model for using near-infrared spectrometry was established using the Karl Fischer method results as a baseline. The moisture content errors were reduced from 1.75% to 0.32% after the correction, which met the requirements for quality control in the actual production process. The combined Karl Fischer and near-infrared spectroscopy method is suitable for the moisture content determination in the whole process of heated tobacco material processing with both accuracy and efficiency, and easy to operate.