Application of Headspace Sampler

What is Headspace Sampling

The Headspace Sampler is a convenient and rapid sample pretreatment method in gas chromatography. Its principle involves placing the sample to be tested into a sealed container, heating it to cause volatile components to vaporize from the sample matrix, reaching equilibrium in the gas-liquid (or gas-solid) phases, and then directly extracting the gas at the top for chromatographic analysis, thereby determining the composition and concentration of volatile components in the sample.

Basic Principle of Headspace Sampling

The test sample is placed in a sealed container, heated to vaporize volatile components from the sample matrix. After reaching equilibrium in the gas-liquid (or gas-solid) phases, the gas at the top is directly extracted for gas chromatography analysis to determine the composition and concentration of volatile components in the sample. The headspace sampling technique eliminates the need for lengthy and complicated sample pretreatment processes, avoids interference from organic solvents in the analysis, and reduces contamination of the chromatographic column and injector.

Headspace Sampling Method

Quantitative Ring Pressure Equalization System

(1) The sample reaches a state of thermal equilibrium after being heated

(2) Pressure is applied to introduce the sample into the quantitative loop

(3) The valve injects the sample into the transmission channel for sampling

Common Applications of Headspace Technology

Environmental Protection

Determination of Volatile Organic Compounds in Water and Soil

Food Industry

Determination of low-boiling point aromatic components in beer; Determination of cyanide in food.

Detection of residual 6# solvent content in extracted oil

Factors Influencing the Results of Headspace Gas Chromatography Analysis

Sample Nature

Samples refer to the original samples placed in the headspace vial, not the volatile substances entering the gas chromatograph, therefore, the properties of the entire headspace vial should be considered.

Sample Quantity

Sample volume refers to the volume of the sample within the headspace vial. The sample volume directly impacts the analysis results.

Balanced Temperature

The equilibrium temperature of the sample is related to the vapor pressure, affecting the distribution coefficient. Generally, the higher the equilibrium temperature, the higher the vapor pressure, the higher the concentration of the overhead gas, and the higher the analytical sensitivity.

Balance Time

Balancing time typically takes longer than analysis time, with the analysis cycle primarily determined by the balancing time. Reducing the balancing time is the key to increasing the speed of static headspace gas chromatography analysis.

Skyline sample bottles and sealed caps, etc.

Most headspace sample bottles are made of borosilicate glass, which has an inert property suitable for the analysis of the vast majority of samples.

Seal washers are primarily made from silicone rubber, fluororubber, and butyl rubber materials.