Gas chromatography - Mass Spectrometry

Gas chromatography - Mass Spectrometry

Uses and Specifications
Chromatography enjoys a high position in today's analytical instruments. Qualitative analysis cannot be conducted with Chromatography alone, because its column has a highly efficient separation capability based on the retention time of the materials and then determine the nature of the material through contrast with that of the samples. However, mass spectrometry can conduct direct determination of the ratio of the mass to the charge ratio (m/z), which is accurate and fast. The combination of chromatography and mass spectrometry is actually using mass spectrometry as a universal detector. There are many detectors of chromatography, such as TCD, FID, ECD, FPD and NPD, etc., each detector has a limited scope of application, which is inconvenient. But as mass spectrometry is universal, it can replace all the other detectors that brings convenience to users.  Therefore, the combination of chromatography and mass spectrometry is a integration of the high-efficient separation of the chromatography and accurate identification of the mass spectrometry to unknown samples. This combination can be used wherever that chromatography is applied. Thus it plays a crucial part among the entire analytic instrument.
The chromatography and mass spectrometry instrument is a product that combines the technologies of chromatography, mass spectrometry and computer.
Working Principle 
Vacuum chamber must be installed in the instrument to ensure the normal operation of the instrument. It adopts a double-level vacuum unit composed of a high-performance turbo-molecular pump and a fore vacuum pump. Samples are separated by capillary column and then enter into the ion source to generate positive ions with electronic power standard (EI) and then the positive ions will be sent into the quadrupole system with the help of aversion, focus and leading of the electrode. The quadrupole system forms into a high-frequency electric field under the influence of high-frequency voltage combined with the positive and negative voltage. And with the scanning voltage, only those consistent with quadrupole equation ions can reach the ion detector through symmetric center of quadrupole. And then it produces mass spectrometry signals after amplification by ionamplifier. Thus mass spectrometry map can be obtained, through which the composition of unknown samples can be identified. Foreign spectral libraries can be configured, such as NIST, WILEY and DRUG.
Applied Range

• wherever that a gas chromatography is needed for detection, especially where qualitative analysis is to be conducted on unknown samples
• Dealing with emergencies such as hazardous materials spills, major environmental disasters
• Combating with terrorism, drug interdiction and explosives analysis