Method for testing tobacco water content based on time domain nuclear magnetic resonance inversion peak area

Abstract

The invention relates to a method for testing tobacco water content based on a time-domain nuclear magnetic resonance inversion peak area. The method is characterized in that a CPMG sequence is used on a time domain time-domain nuclear magnetic resonance, 4-6 of the tobacco standard samples with different qualities are measured, a transverse relaxation spectrum of the standard sample is obtained by SIRT inversion of an original data, a primary peak area of the transverse relaxation spectrum is recorded, the water content of the standard sample is measured by using a microwave drying method, a standard curve of the primary peak area data and the water content of the standard sample is established, the sample with water content to be measured is measured, the obtained primary peak value is substituted into the standard curve, the water content of the to-be-measured sample is obtained, and the water content of the to-be-measured sample is obtained. The interference of an oil signal in a tobacco sample can be eliminated, influence of oil fraction in the tobacco is not generated, detection speed is fast, and the result is accurate. The sample preparation and solvent consumption are not required, the defect that the oil and water signals in the tobacco cannot be distinguished when a nuclear magnetic signal method is used for measuring water content of the tobacco, and the accuracy for measuring the water content of the tobacco oil-water signal sample is increased.

Description

technical field [0001] The invention belongs to the field of time-domain nuclear magnetic resonance in detecting the moisture content of tobacco, and in particular relates to a method for detecting the moisture content of tobacco. Background technique [0002] The moisture content in tobacco is an important quality index in the process of tobacco processing. The methods for determining moisture content in the tobacco industry mainly include oven method, Karl Fischer titration method, gas chromatography, infrared method, microwave method, near-infrared spectroscopy, etc. The two methods of Karl Fischer titration and gas chromatography have relatively high requirements for operators and detection reagents, and the detection time, especially the pretreatment time, is long, and the detection cost is relatively expensive. Although the infrared method and the microwave method have fast detection speeds, the detection results are easily affected by the color, temperature and exter...

AI Technical Summary

Problems solved by technology

Due to the presence of fats and oils in tobacco, the method for measuring the moisture content of tobacco by using the nuclear magnetic resonance signal quantity, such as the method disclosed in CN 103837560 A for measuring the moisture content of tobacco with low-field nuclear magnetic resonance, cannot distinguish the oil-water signal, and the obtained nuclear magnetic resonance signal quantity It is the sum of oil-water mixed signals, which affects the accuracy of measurement results

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