Comprehensive information on Gas Chromatography (GC)
This article describes about Comprehensive information on Gas Chromatography.
Comprehensive information on Gas Chromatography (GC)
What is mean by Gas Chromatography and It’s Principle?
Gas chromatography is a technique used in analytical chemistry to separate and analyze different components of a sample mixture
In GC, a mixture is vaporized and introduced into a column, where it is separated into its individual components based on their physical and chemical properties. The separated components are then detected and quantified using a detector, which measures the concentration of the individual components.
GC is particularly useful for the analysis of volatile and semi-volatile compounds, which can be difficult to analyze using other analytical techniques.
Gas chromatography is used method for the analysis of drugs, drug metabolites, impurities, and other related compounds in the pharmaceutical industry.
It is a sensitive and precise method for the analysis of pharmaceuticals and is commonly used in quality control, research and development laboratories in pharmaceutical Industry.
What are the Types of detectors used in Gas chromatography (GC) ?
Flame Ionization Detector (FID)
Thermal Conductivity Detector (TCD)
Electron Captured Detector (ECD)
Mass Spectroscopy Detector (MSD)
Photoionization Detector (PID)
Which is the most commonly used detectors in Gas Chromatography (GC) in the pharmaceutical industry ?
Flame Ionization Detector (FID) is the most commonly used detectors in pharmaceutical industry because of its has steadfast dependability and sensitivity, Ease of operations when detecting the organic Vapours/Solvents. Most of pharmaceutical industry Gas Chromatography is used to detect the Organic Solvent in drug product.
What type of carrier gaseous used in Gas Chromatography (GC) and what are the examples ?
The Inert and non reactive gases used as carrier gas in chromatography the examples of carrier gasses used in Gas Chromatography is as below.
The choice of carrier gas used in Gas Chromatography (GC) depends on several factors, including the type of sample being analyzed, the type of column being used, and the detector being used. Here are some of the most commonly used carrier gases in GC:
- Helium: Helium is the most commonly used carrier gas in GC because it is inert, low molecular weight, and non-flammable type of nature. It is readily available and relatively inexpensive. Helium is compatible with most types of detectors and does not react with the sample or the stationary phase of the column.
- Hydrogen: Hydrogen is another commonly used carrier gas in GC. It has a low molecular weight, which can help to improve separation efficiency, and it is compatible with some types of detectors, such as the flame ionization detector (FID). However, hydrogen is highly flammable, and special precautions must be taken when using it.
- Nitrogen: Nitrogen is an inert gas that is often used as a carrier gas in GC. It is compatible with most types of detectors and is relatively inexpensive. Nitrogen has a higher molecular weight than helium, which can result in lower separation efficiency, but it can be useful for analyzing large molecules or samples that are prone to adsorption.
- Argon: Argon is an inert gas that is sometimes used as a carrier gas in GC. It is compatible with some types of detectors, such as the mass spectrometer, and can be useful for analyzing certain types of samples. However, argon is more expensive than helium or nitrogen.
How Many Types of Autosamplers used in Gas Chromatography (GC) ?
Liquid Autosampler,
Headspace autosampler
Solid phase microextraction (SPMC)
What is mean by ALS (Auto liquid sampler) and Head space auto sampler in Gas Chromatography (GC) ?
ALS stands for “Automatic Liquid Sampler” and refers to an used in gas chromatography to introduce liquid samples into the gas chromatography system. The ALS automates the process of injecting samples into the chromatograph, which allows for greater precision, accuracy, and throughput compared to manual injection methods.
In gas chromatography, head space analysis is a technique used to analyze volatile compounds in a sample. The sample is heated, and then volatile compounds are released into the head space, which is then extracted and injected into the gas chromatograph for analysis. This technique is commonly used in the analysis of volatile organic compounds in pharmaceuticals industry samples.
What are the Types of Injections used in Gas Chromatography (GC)?
The choice of injection technique depends on the nature of the sample, the analytes of interest, and the analytical requirements of the analysis. There are several types of injections used in gas chromatography (GC) analysis, each with its own advantages and limitations. Here are some of the most common types:
- Split injection: In split injection, a portion of the sample is introduced into the column while the remaining portion is vented to waste. This technique is typically used when the sample contains a high concentration of analytes or complex components that could interfere with the analysis.
- Spitless injection: In Splitless injection, the sample is introduced into the column and the inlet is maintained at a high temperature for a specified period, allowing for complete transfer of the sample onto the column before the split vent is opened. This technique is typically used when high sensitivity is required or when the sample contains trace levels of analytes.
- Direct injection: In direct injection, the sample is injected directly into the column without any prior treatment. This technique is typically used when the sample is relatively clean and the analytes are not easily degraded.
- On-column injection: In on-column injection, the sample is introduced directly onto the column without passing through the inlet. This technique is typically used when the sample contains thermally labile or highly volatile analytes that may be degraded or lost during the injection process.
- Large volume injection: In large volume injection, a larger volume of sample is introduced onto the column, typically using a special injection technique or hardware. This technique is typically used when the sample is dilute or when high sensitivity is required
What is Split Ratio in Gas Chromatography (GC) ?
Split ratio in gas chromatography (GC) refers to the ratio of the amount of sample that is directed to the column versus the amount of sample that is vented to waste. In a split injection, only a portion of the sample is directed to the column for analysis, while the remaining portion is vented to waste.
For example, a split ratio of 10:1 means that for every 10 parts of sample, 1 part is directed to the column and 9 parts are vented to waste. Split ratios are important parameters to optimize in GC analysis to obtain the best separation and sensitivity for the target analytes in the sample.
Why this Technique is called as Gas chromatography (GC) ?
As the Gas (Inert/Non reactive) used as a mobile phase in the chromatography technique so this technique is called the Gas chromatography .
Commonly used Mobile and Stationary phases used in the Gas chromatography ?
Below are the Mobile and stationary phases used in the Gas chromatography.
Mobile Phase : Gas Stationary Phase : Solid or Liquid
What is mean By Gas Liquid Chromatography ?
The chromatography Techniques in which Mobile Phase is gaseous state and Stationary Phase is in the liquid state for that technique is called as Gas Liquid Chromatography.
What is mean By Gas Solid Chromatography ?
The chromatography Techniques in which Mobile Phase is gaseous state and Stationary Phase is in the Solid state for that Technique is called as Gas Liquid Chromatography.
What is mean by GCMS (Gas Chromatography Mass Spectroscopy) ?
In the Gas chromatography when detector used as Mass spectroscopy then it is called as Gas chromatography Mass spectroscopy (GCMS).
