Method for determining free nicotine in tobacco

Abstract

The invention discloses a method for determining free nicotine in tobacco, which comprises the following steps of: (1) drying a tobacco leaf or tobacco shred sample at the temperature of less than or equal to 40 DEG C, crushing, and performing sieving by using a 60-mesh standard sieve; (2) accurately weighing 0.10 g of the sieved sample powder, adding the sample powder into a 100mL SCHOTT sample bottle, accurately adding 50.0 mL of a cyclohexane solution containing anethole, allowing the cyclohexane solution to contain 10.0 [mu] g/mL of anethole, and standing thecyclohexane solution at 22 +/-2 DEG C for 24 +/-2 h to obtain a solution to be detected after standing; and (3) filtering the solution to be detected after standing by adopting a 0.2 mu m Nylon 66 needle cylinder type filter, and then carrying out GC-MS (Gas Chromatography-Mass Spectrometer) analysis. The detection limit of the analysis method is 5.3 mu g/g, the relative standard deviation is 1.7-2.7% (n is equal to 5), the linear correlation coefficient of a standard solution is 0.9997, and the adding standard recovery rate is 99.0-106.7%. The determination method is simple to operate and accurate in result, and avoids the transformation influence of the aqueous solution on the original nicotine form distribution in the tobacco.

Description

technical field [0001] The invention relates to accurately measuring the content of free nicotine in tobacco, more specifically, the invention relates to a method for measuring free nicotine in tobacco. Background technique [0002] Nicotine is the most important specific component in tobacco, which has a very important impact on the sensory quality of cigarettes. From the perspective of molecular structure, nicotine is a weak secondary base composed of a pyridine ring and a hydrogenated pyrrole ring. When in contact with an acidic component, it can capture up to two protons to form a salt. Therefore, nicotine can be free, single proton and Three forms exist in the diproton state. In tobacco, nicotine usually exists in the state of combining with inorganic acid or organic acid to form a salt, and a small amount exists in the form of free nicotine. Free nicotine has strong lipophilicity and is easy to penetrate through human oral mucosa and be absorbed, resulting in strong ...

AI Technical Summary

Problems solved by technology

The disadvantage of this method is that the actual test sample is generally a solid or quasi-solid heterogeneous system. After being configured into a solution, since the sample to be tested contains a variety of acidic or alkaline components, these components together form the prepared solution. At

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