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Gas Chromatograph

Gas Chromatograph
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In many branches of natural science, one of the first and foremost methods for analyzing and decomposing of an unknown matter into its components is the use of one of the instruments belonging to large group of analytical separation methods called Gas Chromatography (GC). As implied by its name, these methods are only able to analyze volatile substances in the gas phase. However, this is not necessarily considered a serious limitation, because many of materials can be prepared as liquid solution, which then can be injected to the GC instruments.
The heart of GC consists of a separating column which may be placed in an oven. Inside the separating column, a substance called stationary phase is immobilized in a form of deposited layer over surfaces of particles that are accommodated in the column. However, sometimes the separating column uses capillary tubes whose inside walls coated with a thin layer of stationary phase. The latter type is known as packed column, and the former type is known as capillary column. In both columns, the stationary phase must be chemically inactive and have high thermal stability; its thermal stability must be at least 100 °C higher than the maximum temperature of an oven which enclose the column.
The Gas Chromatography principles are very similar to fractional distillation, in which a complex chemical is separated into its constituents because of the difference in boiling point and vapor pressure. Similarly, in GC a complex chemical is injected into a gas stream called carrier gas. The carrier gas is responsible for transferring the whole complex chemical (with all constituents) through the column from the beginning to the end. Chemical constituents have different vapor pressures; therefore, they have different affinities with the stationary phase immobilized inside the column. As a consequence, although all constituents go into the column at the same time, but they come out of the column gradually in separated intervals. And in this way a complex chemical breaks apart into its constituents.
The other important part of any GC instrument is its detectors which are connected to the end of separating column. Detector task is chemical or physical analysis of the separated constituents (analyte). The two most common types of detectors are Flame ionization detectors (FID) and Thermal conductivity detectors (TCD). The latter uses a flame to wholly decompose an analyte into ions and electrons; therefore, the flame becomes conductive toward electricity. The electrical conductivity is then used as a criterion for determination of molecular weight and concentration. The FID detectors have high sensitivity and are useful for the analysis of organic compounds. The main disadvantage of these detectors is that they cause damage to the analyte. On the other hand, TCD detectors estimate the amount of analyte in carrier gas by measuring the carrier gas thermal conductivity. Being a non-destructive analysis tool is the main advantage of TCD detectors, so it is possible to collect the analyte after separation and detection. The greatest drawback of the TCD is its low sensitivity compared to the other detection methods.
Some applications of this device are as follows: 
  • Petroleum and petrochemistry
  • Food and flavors
  • Pharmaceutical industry 
  • Environmental protection 
  • Chemistry laboratories
One of the best choices of gas chromatography devices is the GC-2552 model which provides superior performance for all chromatography applications. Details of technical specifications are presented in the following Table.
 

High speed

High resolution

High accuracy

High reproducibility

High quality

FID detector as default

TCD detector (Optional)

Split flow control by MFC and setting via software

Capillary injector (Split/Spllitless)

Capillary inlet pressure by EPC (Optional)

H2 and Air flow control by MFC (Optional)

Online injection by 6 port valve (Optional)

PID temperature control

Oven temperature programming via software (for any step)

Online software help in any language

Friendly user software

  • For installation of the system, use a proper table with dimensions of 150×70 cm, capable of bearing 50 Kg weight.
  • The installation room should be in an isolated environment with sufficient ventilation. 
  • Keep away the device from direct sunlight.
  • Keep away the device from wind. 
  • The product should be kept away from any heating sources (radiator) or cooling system (cooling fan). 
  • A gap of at least 30 cm should be left between the backside of unit and the facing wall. This gap is useful because during cooling facilitates the device exhaust gas ventilation.
  • For more details on how to use the device, refer to the device catalog and user guide.
  • It is strongly recommended that all dangerous hydrogen cylinders are replaced with a safe hydrogen generator. 
  • Proper ventilation is necessary for the laboratory because in case of emergency and hydrogen leakage, hydrogen gas could be promptly depleted from the laboratory atmosphere. 
  • Proves a safe place outside the laboratory to convey exhaust gases from split purge and septum purge. 
  • Daily inspection of the septum and column integrity, before running the system, is necessary.
  • Before turning on the TCD filament, make sure that the carrier gas flows inside the column. 

Product Standard

  • NanoScale Certification

    NanoScale Certification

    Standard Date : 2017/11/21

    Expire Date : 2020/11/21

  • Certificate of Nanotechnology

    Certificate of Nanotechnology

    Standard Date : 2017/11/21

    Expire Date : 2020/11/21

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