Comprehensive flavor analysis system GC-O-MS

GCOMS(Gas ChromatographyOlfactometryMass Spectrometry)It is a combination of gas chromatography(GC)Olfactory detection(Olfactometry)And mass spectrometry(MS)The combination technology is widely used in the analysis of flavor compounds in fields such as food, spices, cosmetics, etc. It can not only separate and identify volatile compounds, but also determine their contribution to flavor through sensory evaluation.

Principles and processes

1. gas chromatography(GC)

Separate volatile compounds from the sample.

By chromatography column and carrier gas(Like helium gas)Implement separation.

2. smell test(Olfactometry)

The compounds separated by chromatography are passed through a splitter, with a portion entering the mass spectrometer and another portion entering the sniffing port.

The sensory evaluator sniffes the odor through their mouth and records the characteristics and intensity of the odor.

3. mass spectrometry(MS)

Identify the separated compounds and provide molecular weight and structural information

instrument composition

1. gas chromatograph

Chromatography column: commonly used capillary column(asDB5).

Injection system: liquid or headspace injection.

2. shunt

Divide the effluent into two parts and enter the mass spectrometer and sniffing port respectively.

3. Sniffing port

Equipped with a humidification device to prevent sensory evaluators from experiencing dry nasal passages.

4. mass spectrometer

Common electron bombardment ion sources(EI)And quadrupole mass analyzer.

sample pretreatment

1. Extract volatile compounds

Headspace injection(HS)Suitable for high volatility compounds.

Solid-phase microextraction(SPME)Adsorption of volatile substances through fibers.

Solvent extraction: using organic solvents(Like dichloromethane)Extract.

2. Concentration and Purification

Concentrate low concentration samples(Like nitrogen blowing).

Remove interfering substances(Such as fat and protein

data analysis

1. Odor activity value(OAV)

Calculate the ratio of compound concentration to its olfactory threshold and evaluate its contribution to flavor.

2. Dilution analysis of aroma extract(GRUNTS)

Determine key aroma compounds by gradually diluting the sample.

3. Mass spectrometry database matching

useNISTIdentify compounds in the mass spectrometry library.

Application field

1. Food Science

Analyze key aroma compounds in food(Such as coffee, wine, dairy products).

Study the influence of processing technology on flavor.

2. Spices and cosmetics

Identify the key components in spices.

Evaluate the stability and release characteristics of essence.

3. Environment and Tobacco

Analyze odor substances in the environment.

Study the aroma components produced by tobacco combustion.

Advantages and limitations

1. advantage

Combining sensory evaluation and chemical analysis, comprehensively analyze the flavor.

High sensitivity and high resolution.

2. 局限性

Sensory evaluation is influenced by individual differences.

Sample pre-treatment is complex and may result in loss of volatile substances.

research hotspot

1. New sample pretreatment technology

Develop more efficient extraction and concentration methods(Like dynamic headspace extraction).

2. Multi group collaborative technology

Combining metabolomics and genomics to study the molecular mechanisms of flavor formation.

summary

GCOMSIt is a powerful flavor analysis tool that combines chemical analysis and sensory evaluation, widely used in fields such as food and spices. In the future, with the advancement of sample pretreatment technology and data analysis methods,GCOMSWill play a greater role in flavor research.