This article describes a method for determining the water content in tobacco using near infrared spectroscopy, and compares it with oven drying and Karl Fischer titration. The method allows for accurate and reproducible measurement of water content.
The document details the development and evaluation of a method to accurately measure water content in tobacco samples using near infra-red (NIR) spectroscopy. This technique was compared against traditional methods like oven drying and Karl Fischer titration, showing superior specificity and precision for this application.
The procedure involves extracting water from tobacco leaf form into dry methanol, followed by scanning the extract between 1800-1950 nm using a Cary 5 double beam spectrophotometer. The method utilizes a specific program written in the Cary 5E Application Development Language (ADL) to automate measurements and calculations based on absorbance at 1943 nm.
Methanol was found to be the most suitable solvent as it provides rapid extraction at room temperature and a reproducible calibration curve.
The absorbance of the peak is measured at 1943 nm after subtracting the background absorbance.
A Cary 5 double beam spectrophotometer covering the 175-3300 nm range is used.