The GC vials have an essential role in the gas chromatograph process. They are used for various purposes including storage and sampling of the sample. They can be either glass or polypropylene. They are available in a variety of sizes and shapes. Some important parameters to be kept in mind while using GC vials include the pressurization delay time, the length of the column, the type of liner, and the possibility of re-use of the vial and closure.
GC vials
A GC vial is a glass container used for storing and analyzing samples in gas chromatography. There are many types of GC vials on the market. Commonly, they are made of Type 1 Class A Borosilicate glass, which has good chemical resistance and temperature resistance properties. However, other glass containers may be used.
To ensure maximum sample integrity, GC vials must be closed with a crimp or snap top. These vials are commonly used in HPLC and forensic lab settings, but can also be found in medical and legal industries. Some GC vials are sold individually or as part of a chromatography kit.
Various headspace sampling methods have been developed over the years. The most common technique involves pressurization with inert gas. This method has the advantage of producing a uniform pressure that is easily controlled and allows for precise timing.
Column length (m)
In GC, a capillary column is a thin glass tube with an internal liquid phase coating. It has advantages over packed columns. It is able to separate large volumes of samples, which are not possible with a packed column. It also achieves high separation performance and is suited for high-sensitivity analysis.
There are two main ways to coat a GC column: chemical vapor deposition and dynamic coating. The dynamic method moves the solution through the column by applying a differential gas pressure. During this process, the film thickness is dependent on the initial concentration of the stationary phase. If the film is not uniform, it may decrease the efficiency of the column. The PDMS dynamic coating method has been used in MEMs columns.
Liner type
Choosing the right liner for GC vials is essential for ensuring that a sample is vaporized and transferred to the GC column. Depending on the type of sample and the GC method, a variety of liners are available.
Several factors should be considered when selecting a liner, such as the sensitivity of the sample and the expansion volume of the solvent. Too large an expansion volume can lead to poor sensitivity and a carryover effect of the GC system.
Active samples require heating and fast cooling. If these conditions are not used, the analyte components may be degraded and peak tailing can occur. This can result in ghost peaks.
Ideally, the liner should not react with the sample and should provide an inert surface for transfer of the liquid sample to the GC column. For aqueous solutions, a narrow bore liner is best. The internal diameter of the liner should be sufficient to accommodate the volume of sample that will be vaporizing.
Pressurization delay time
The pressurization delay time of GC vials is an important variable in gas chromatography. It can affect the accuracy and precision of the analysis.
The GC can analyze both liquids and solids. This type of analysis requires fewer steps than analytical methods that require derivatization and solvent separation. GC can also be used to analyze gaseous samples.
Typical sample preparation includes preparing a sample matrix. These are different depending on the type of sample. For a solid sample, the matrix may be powdered. The method to prepare the sample matrix may involve several steps. It is essential to choose the most appropriate sample preparation method. This will help in improving the precision of the method.
For a liquid sample, the pressurization delay time should be shortened. This will prevent damage to source filaments.
Re-use of vials and closures
Gas chromatography is one of the most commonly used environmental chromatographic techniques. This technique allows for the analysis of a wide range of organic compounds. It also provides information about the chemistry of the sample matrix.
When using gas chromatography, it is important to determine the type of gas to use. This depends on the sensitivity of the detector and the system’s tolerance for impurities. Generally, inert gas is used. However, if the sample is highly volatile, an oxidizing carrier gas may be preferred.
In addition, there are different types of vials to consider. For example, glass vials are more suitable for strong organic solvents. They are more resistant to UV rays and they are available in many shapes and sizes.
