Gas Chromatographic Analysis of Tobacco Flavors

Since the inherent quality and stability of cigarette flavors and fragrant raw materials have a considerable impact on the quality stability of cigarette products, the improvement of product quality and stability is one of the important production steps. Therefore, the detection and analysis of flavor and fragrance products The importance is gradually emerging. The conventional tests for the inherent quality of flavors and fragrances for cigarettes mainly include physical and chemical testing items such as acid value, clarity, total volatile components, color intensity, density, refractive index, and volume mix. These traditional detection indexes are inherent to flavor and fragrance products. Quality control plays a better role. In recent years, with the improvement of equipment and operation technology level of cigarette companies and flavor and fragrance companies, the quality control of fragrances has become more stringent, with more emphasis on the detection and analysis of the internal components of cigarette essences, which has improved the level of control over the quality of flavors and fragrances. The scientific monitoring of the intrinsic quality components of the flavor and fragrance products can be realized, which is beneficial to the rational grasp and rational use of the flavor and fragrance products by the flavor and fragrance companies and the cigarette enterprises, thereby promoting the improvement of product quality stability.

§ 11-1 Detection and Analysis Contents 1. Sampling Sampling refers to taking samples representative of quality and composition from a batch of containers or a container for analysis and inspection.

All tools used in sampling should be washed and dried before use. The tools used should be made of materials that are not subject to sample corrosion.

Sampling method (1) Sampling of large-capacity containers If the product is contained in a large-capacity container such as a large tank or a tank truck, the total depth of 1/10 of the total depth, 1/3 of the volume, is taken out from the upper surface in each large-capacity container. 5 local samples with total depth, 1/2 total depth, 2/3 total depth, and 9/10 total depth. Collect the 5 local samples obtained in each container, mix well, and remove 3 from them. Representative samples are used for quality inspection and black-to-analysis.

(2) Sampling of general containers If products are contained in barrels, altars, cans or bottles, the samples of different concentrations shall be taken from each container according to the minimum number of sampling containers listed in Table 11-1, and then mixed together. Evenly, three representative samples were sampled from it for quality inspection and analysis.

Table 11-1 Sampling scale commissioned analysis Total number of containers Minimum number of sampling containers Total number of containers to be analyzed Total number of sampling containers 1 to 3 Each container 61 to 805

4～20381～1206

For each 20 containers above 21 to 604120, take two. Preparation of Samples In order to obtain qualified test samples, the following procedures should be taken:

(1) Filling the sample If the essential oil is liquid at room temperature, it can be poured into the Erlenmeyer flask at room temperature. The amount of the oil does not exceed 2/3 of the volume of the container. If the essential oil is solid or semi-solid at air temperature, it should be placed in an oven, controlled at a suitable temperature for liquefaction, and then filled. In later operations, the essential oil is always kept at the lowest temperature of the liquid.

(2) Drying of the sample In natural essential oils, the sample often contains trace amounts of moisture. In order to remove trace amounts of moisture, a newly dried neutral dehydrating agent magnesium sulfate or sodium sulfate should be added to the Erlenmeyer flask containing the sample to be tested. Among them, the amount added was about 15% of the quality of the essence, and it constantly oscillated violently for at least 2 hours.

(3) Decolorization of the sample For a sample with a darker color due to the presence of a metal or metal oxide, decolorization may be performed with citric acid or tartaric acid. By stirring an appropriate amount of citric acid or tartaric acid with the essential oil, the metal ions in which the essential oil produces color can be removed.

(4) After the sample is filtered and dried, decolorized, etc., the sample should be filtered and placed in a clean and dry container. All tests should be carried out as required.

Third, the test content 3.1 essential oils are liquids. Some essential oils crystallize or solidify at low temperatures. Such samples should be slowly heated until they are all liquid. First, the sample should be evaluated for appearance (ie color, clarity), preferably compared to a retained sample, and then the product is dissolved in a thin syrup for evaluation of aroma and aroma.

(1) Relative test item relative density (usually determined at 25°C/25°C, corrected at any other temperature measurement);

Refractive index (20°C);

Optical rotation (20°C);

Solubility (solubility in ethanol at a specific dilution).

(2) Application of limited experimental boiling range (°C);

Melting point (°C);

Freezing point (°C);

Flash point (F° or °C) using open cup or lid cup method.

(3) Instrumental tests Gas chromatography, liquid chromatography, infrared spectroscopy, ultraviolet spectroscopy (identity and source determination, determination of doping, compositional changes, and production quality control, selection of mathematical model for fingerprinting studies: study to determine the best fingerprint Mathematical model of the map.Determination of the tolerance index of the chromatographic fingerprint of tobacco flavor and fragrance products: through the influence of different production batches of flavors and fragrances, different storage time and storage conditions, simulation of raw materials and ratio changes on chromatographic fingerprints, combined with aroma quality and The evaluation of the aroma quality determines the tolerance index of the chromatographic fingerprint of the tobacco flavor and fragrance products.

(4) Specific test acid values ​​for the components;

Alcohols; acetic acid-formaldehyde method was used to measure the total amount of alcohols and tertiary sterols, and formic acid was used to measure the amount of citronellol;

Aldehydes and ketones: bisulfite method, neutral sulfite method, phenylhydrazine method, hydroxylamine method.

Chlorine compounds;

Esters: common method, high boiling point solvent method;

Heavy metal

Phenols: free phenols, total phenols.

3.2 Synthetic perfumery samples may be liquid or crystalline solids, and items to be tested are often determined by their final use. Conventional physicochemical tests are necessary to control purity, but compounds used for food flavors or daily fragrances are more important for the evaluation of their aromas and aromas.

(1) Relative liquid density (usually measured at 25°C/25°C, corrected at any other temperature measurement);

Refractive index (20°C);

Optical rotation (20°C);

Solubility in a certain concentration of ethanol or other specific solvents;

The boiling point (°C) at a given pressure;

Freezing point/freezing point (°C);

Flash point (F° or °C) using open cup or lid cup method.

(2) Solid melting point (°C);

Freezing point (°C);

Solubility in specific solvents;

Does not contain insolubles.

(3) Special tests for the determination of chemical identity and purity - instrumental analysis gas chromatography (GC);

Liquid chromatography (HPLC);

Infrared spectroscopy (IR).

3.3 Tobacco Flavors Flavors used in tobacco can be liquids, emulsions or dry powders. The appearance of the sample (ie, color, clarity, opalescence) was first evaluated, and the sample was then diluted with a suitable medium to evaluate its aroma and aroma. It is best to perform a direct comparison with a standard sample that is stored under optimal conditions and replaced at the specified time.