Chemical ionization mass spectrometry

Chemical ionization mass spectrometryCan measure substances such as organic acids, aldehydes, halogens, nitro chlorides, free radicals, etc. According to its functions, it is mainly divided into three parts:

1) Sample introduction and ionization zone;

2) Ion transport system;

3) Flight time quality analyzer. The workflow of the instrument is as follows: the sample gas is introduced through a conical microporous injection device, while the reagent gas, methane, is irradiated by a vacuum ultraviolet krypton lamp to generate reagent ions. The sample gas molecules mix and collide with each other under the action of the gas flow field to form iodine adduct ions, which enter the fragment quadrupole through micropores for preliminary focusing by the radio frequency electric field. They then enter the long quadrupole through the skimmer 1 electrode for further focusing, and enter the pulse repulsion zone of the time-of-flight mass analyzer through the slit after being shaped by the lens through the skimmer 2 electrode. The ion beam enters the acceleration zone under the action of high pulse repulsion frequency pulse voltage, and after dual field acceleration, it sequentially enters the field free flight zone, the reflection zone, and then returns to the detector surface. After receiving the ion signal, the detector transmits it to the analog-to-digital conversion card (ADC), and then the data acquisition system and data processing software draw a two-dimensional spectrum of signal intensity and flight time. After mass calibration, the flight time is matched with the mass to charge ratio to obtain the mass spectrum.

Chemical ionization mass spectrometryApplication field

Environmental monitoring: used to detect volatile organic compounds (VOCs), organic acids, alcohols and other pollutants in the atmosphere and water bodies.

Food safety: Analyze additives, pesticide residues, flavors, and other components in food.

Pharmaceutical analysis: used for qualitative and quantitative analysis of drugs, especially compounds that are thermally unstable or prone to decomposition.

Organic synthesis: Monitor the intermediates and products of organic synthesis reactions and optimize reaction conditions.

Biomedical: Analyze metabolites, lipids, proteins, etc. in biological samples to study biological processes.

Petrochemical industry: Analyze the components in petroleum products and evaluate product quality.