At present, among analytical instruments, chromatography instruments have an important position. Because the column of the chromatograph has high-efficiency separation ability, the substance is separated according to the retention time, and then the nature of the substance is determined by comparing with the retention time of the standard sample, so it is difficult to qualitatively analyze the unknown sample. The mass spectrometer directly measures the mass ratio of the substance to the charge (m / z), which is both accurate and fast in qualitative analysis. Combining chromatography and mass spectrometry, the type test of gas chromatography-mass spectrometry actually uses the mass spectrometer as a general detector of the chromatograph.
There are many detectors in the chromatograph, such as TCD, FID, ECD, FPD, NPD, etc. Each detector has only a limited scope of application and cannot be used universally, causing inconvenience in use. As a mass detector, mass spectrometer can replace multiple detectors of chromatograph. It has strong versatility and is extremely convenient to use. Therefore, gas chromatography-mass spectrometry combines the high-efficiency separation of chromatography with the accurate identification of unknown samples by mass spectrometers, and improves the analytical instruments to a new level. Wherever chromatographs can be used, color-quality can be used. Combined instruments. At present, it is recognized internationally that the color-mass spectrometry instrument occupies a very prominent position in the current instrument analysis. Gas chromatography-mass spectrometry is a product of three modern technologies, such as chromatography, mass spectrometry and computer technology. Due to the difficulty of technology, China has been unable to produce, and it has to spend a lot of foreign exchange imports every year. According to statistics, about 600 sets of various color-mass spectrometers were imported in 2005 in China.
The average selling price of each set is 60 ~ 1 million RMB. The company independently developed and successfully developed a gas chromatography mass spectrometer. This is China's first commercial color-mass spectrometer, and its technical indicators are close to the current international advanced technology level.
Application range of gas chromatography mass spectrometer
1. Wherever a gas chromatograph is required for testing, especially where qualitative analysis is performed on unknown samples
2. Respond to various emergencies, such as leakage of hazardous substances, major environmental disasters, etc.
3. The fight against terrorism, anti-drug and anti-drug, analysis of explosives, etc.
Basic working principle of gas chromatography-mass spectrometer
In order for the mass spectrometer to work properly, a vacuum chamber of a high vacuum system must be formed. The instrument uses a high-performance turbo molecular pump and a fore-stage vacuum pump to form a two-stage vacuum unit to ensure the required vacuum. The analyzed sample is separated by a capillary column and enters the ion source. The electronic power standard configuration (EI) is used to generate positive ions, and the positive ions are sent to the quadrupole system under the action of repelling, focusing, and extracting electrodes. The quadrupole forms a high-frequency electric field under the combined action of high-frequency voltage and positive and negative voltages. Under the effect of the scanning voltage, only ions that conform to the quadrupole field motion equation can reach the ion detector through the quadrupole symmetry center, and then pass the ion current. The amplifier amplifies to produce a mass spectrum signal. The mass spectrum is obtained, and the composition of the unknown sample is identified by interpreting the spectrum or performing a library search.
Mini Mummy Bags are becoming more and more popular as regular items for babies and parents. Whether it is a long-distance travel or a short trip, the Mummy Bag provides important convenience for babies and parents. The popularity of mommy bags has caused new parents to pay attention to infant travel, not only psychologically but also physical changes, with great significance.
Kids Mummy Bag,Mini Mummy Bag Backpack,Small Mummy Bag,Mini Mummy Bag
JOYBABIES PRODUCT CO.,LTD. , https://www.my-joybabies.com