Valve Injection Gas Chromatographs
Description
Valve Injection Gas Chromatographs are analytical instruments designed to separate and analyze compounds that can be vaporized without decomposition. They consist of a flowing mobile phase, an injection port, a separation column with a stationary phase, and a detector. These devices are used to separate organic chemical mixtures based on their physical properties, allowing for the identification and quantification of the individual components within a sample.
Working Principle
The working principle of Valve Injection Gas Chromatographs involves the use of a carrier gas to transport the sample through the system. The sample is introduced into the system via an injection valve, which is actuated to allow the carrier gas to push the sample into the separation column. Inside the column, the sample components are separated based on their partitioning behavior between the mobile phase and the stationary phase. As the components elute from the column, they are detected by various types of detectors, such as thermal conductivity detectors or flame ionization detectors. The detector signals are processed to produce a chromatogram, which is used to calculate the concentrations and other physical properties of the sample components. This method is useful for its ability to provide detailed analysis of complex mixtures with high precision and accuracy.
Applications
Valve Injection Gas Chromatographs are used in a wide range of applications. They are commonly employed in the analysis of agricultural chemicals and pesticides, cosmetics and fragrances, drugs and pharmaceuticals, and food and beverage processing. In the energy sector, they are used for environmental monitoring and the analysis of industrial gases. Additionally, they play a crucial role in forensics and narcotics detection, as well as in the analysis of petroleum products and plastics.
Advantages over other Gas Chromatographs
Valve Injection Gas Chromatographs offer several advantages over other types of gas chromatographs. They provide precise control over the sample injection process, which can lead to improved accuracy and repeatability in the analysis. The use of multiple valves and columns allows for complex separation processes, such as back-flushing and dual-column arrangements, which can enhance the separation of components and reduce analysis time. These systems are also capable of handling a wide range of sample types and concentrations, making them versatile tools for various analytical applications.
Limitations
One of the primary limitations of Valve Injection Gas Chromatographs is the requirement for samples to be volatile at the column operating temperature. This can restrict the types of compounds that can be analyzed using this technique. Additionally, the complexity of the system, with its multiple valves and columns, can lead to increased maintenance requirements and potential for mechanical failure.
Considerations
When considering the use of Valve Injection Gas Chromatographs, several factors should be taken into account. Initial costs can be high due to the complexity and precision of the equipment. Operating expenses may also be significant, as the system requires a continuous supply of carrier gas and regular maintenance to ensure optimal performance. Durability and accuracy are generally high, but the system's complexity can lead to increased maintenance and replacement costs over time. It is important to evaluate these factors in the context of the specific analytical needs and budget constraints of the intended application.
from ABB Measurement & Analytics
The PGC5007 performs a Total sulfur analysis for a range of streams, liquid and vapor, from natural gas to gasoline and diesel. A fixed volume of sample from the process stream is injected via a sample inject valve. Air transports the sample into the furnace, where it oxidizes the sample to carbon... [See More]
- Injection Method: Valve Injection
- Application: Sulfur Analyzer
- Instrument Type: Fixtured
- Oven Operation: Isothermal; Temperature Programmable
from ABB Measurement & Analytics
The challenge. A relatively small shift in the cut point for any refinery product can cost refiners millions in profits. In the absence of fast, accurate and reproducible boiling point data, refinery product yields are not optimized and more importantly, profits are lost. The solution. The PGC5009... [See More]
- Injection Method: Valve Injection
- Application: Energy; Petroleum; Gasoline, Diesel
- Instrument Type: Fixtured
- Oven Operation: Oven; Temperature Programmable
from Envent Engineering Ltd.
The TCD and injection valve and columns utilized in the 131/132 are timeproven devices. The electronic platform is unique to the 131/132 system and provides on-line, real-time analysis as well as a full list of configurable features for data handling, alarm functions and special functions. The... [See More]
- Injection Method: Valve Injection
- Display: Digital
- User Interface: Digital
- General Features: Built-in or Self Calibration; Data Storage
from Siemens Analytical Products
This process gas chromatograph, which has resulted from decades of international experience and technology development, leads the industry in capability, flexibility and reliability. The Maxum edition II is used in all branches of the fine chemicals, refining and hydrocarbon processing industries. [See More]
- Injection Method: Valve Injection
- Application: Industrial Gases
- Instrument Type: Fixtured
- Oven Operation: Isothermal
from Emerson Automation Solutions – Rosemount
The 1500XA Process Gas Chromatograph combines the proven analytical components of the field-mounted GCs with the larger oven capacity of a traditional air-bath oven design. The result is maximum analyzer reliability and analytical flexibility in one package. The Rosemount Analytical 1500XA Gas... [See More]
- Injection Method: Valve Injection
- Application: Environmental; Industrial Gases; Refineries, Petrochemical, Gas Processing, Power Generation
- Instrument Type: Fixtured
- Oven Operation: Oven
from O. I. Analytical
Automated sample injection (gas or LPG), calibration, and QA/QC [See More]
- Injection Method: Valve Injection; Split/Splitless Column Injection
- Application: Organic Chemicals
- Instrument Type: Fixtured
- Oven Operation: Oven; Isothermal
from Emerson Automation Solutions – Rosemount
The Danalyzer 370XA Gas Chromatograph from Emerson Process Management is the latest analyzer to join the XA Series of Rosemount Analytical gas chromatographs. The 370XA is designed to simplify natural gas measurement analysis in Fiscal and Custody Transfer applications and improve the measurement... [See More]
- Injection Method: Valve Injection
- Application: Environmental; Industrial Gases; Natural Gas Applications: Custody Transfer, Production Gas Measurement, Power Generation, Gas Burner Management
- Instrument Type: Fixtured
- Oven Operation: Isothermal