Introduction to the factors affecting the headspace gas chromatograph
The content expressed in this article is Introduction to the factors affecting the headspace gas chromatograph please feel free to contact me.
The use of headspace technology eliminates the lengthy and cumbersome sample preparation process, avoids interference caused by organic solvents, and reduces contamination of the column and inlet. Headspace chromatography technology is simple and practical in the environment. Testing (such as volatile halogenated hydrocarbons in drinking water and volatile organic compounds in industrial wastewater), detection of organic residual solvents in pharmaceuticals, food, forensic science, petrochemicals, packaging materials, coatings and wine industry analysis are widely used.
Factors affecting the headspace gas chromatograph
(1) Effect of heating temperature: It is necessary to ensure that volatile substances are volatilized from the sample and achieve a stable dynamic balance. The higher the heating temperature, the more volatile substances are measured by the interference, and the appropriate temperature is selected to reduce the interference. Alternatively, if the sample is in a high temperature thermostat, injection at room temperature will condense the higher boiling component. :
(2) Effect of activity coefficient: Adding electrolyte or non-electrolyte to the product can increase the activity coefficient and determine the activity. (3) Effect of pressure: The sample gas sealed in the container rises at an elevated temperature, the pressure is greater than the atmospheric pressure of the outside, and the sample is taken from the container with a syringe, which causes an error.
(4) Influence of space: . The volume of the upper space should be moderate, and the smaller one can increase the sensitivity, but if it is too small, the phase balance is not easy to be achieved, and the sampling is not easy to be uniform.
(5) Influence of the feeder: The sampling cannot be as fast as taking the liquid sample. The core welding should be lifted slowly, and the inner wall of the injector is wetted with a little distilled water before sampling to make the wall and core weld more tight.
In addition, the size of the vaporized bottle and the amount of sample should be considered.
The above content is Introduction to the factors affecting the headspace gas chromatograph I hope it will help you!