Determination of β2 stimulants in animal tissues by gas chromatography-mass spectrometry

Summary

Gas Chromatography-Mass Spectrometry (GC-MS) is an analytical instrument that measures the ion charge-to-mass ratio (charge-to-mass ratio) and can be used for (1) characterization and quantification of small molecule compounds (2) characterization and quantification of volatile compounds (3) contaminants on semiconductor surfaces and (4) analysis of proteins on biological tissues.

Operation method

Gas Chromatography-Mass Spectrometry

Principle

Gas chromatography-mass spectrometry instrument adopts gas chromatography to separate the components in the sample, which plays the role of sample preparation; the interface sends the components out of gas chromatography into mass spectrometer for detection, which plays the role of adapter between gas chromatography and mass spectrometry; mass spectrometry analyzes the components introduced into the interface in turn, which becomes the detector of gas chromatography; the computer system interactively controls the gas chromatograph, the interface, and mass spectrometry, and thus obtains the data of chromatography and mass spectrometry for qualitative and quantitative analysis of components in complex samples. The computer system interactively controls the gas chromatograph, the interface and the mass spectrometer to collect and process the data, thus obtaining the chromatographic and mass spectrometric data and analyzing the components in the complex sample qualitatively and quantitatively.

Materials and Instruments

Animal Tissue
Salbutamol Sulfate Clenbuterol Hydrochloride Terbutaline Sulfate Methanol Ethyl Acetate Isopropyl Alcohol Perchloric Acid Sodium Hydroxide Toluene Anhydrous Sodium Sulfate TMCS Silica Gel Amine-based Alumina
Gas Chromatography-Mass Spectrometer Rotary Evaporator Ultrasonic Cleaner High-Speed Tissue Pounder

Move

1、Weigh 5.0 g of stranded sample, add 30 ml of 1% perchloric acid solution;

2, homogenize in a high-speed tissue homogenizer for 1 min, sonicate at 80 ℃ for 15 min, centrifuge at 5000 r/min for 10 min, and transfer the supernatant to a separatory funnel;

3、Adjust to alkaline with 50% sodium hydroxide, add 30 ml of organic solvent, centrifugation, the organic phase was transferred to a triangular flask with stopper, and the extraction was repeated once;

4, combined organic phase, through anhydrous sodium sulfate, rotary evaporation at 50 ℃ to dry;

5, first 3 ml of acetonitrile and 3 ml of hexane dissolved and transferred to the test tube, mixing and then separated from the hexane phase, acetonitrile phase evaporated and then dissolved in 3% ethanol / ethyl acetate volume to 2 ml. The Cle-SLX column was first rinsed with 5 ml of 3% ethanol/ethyl acetate, and then 1 ml of sample extraction solution was added. 5 ml of 5% methanol/ethyl acetate was added to collect component 1, and then 10 ml of 50% methanol/ethyl acetate was added to collect component 2, and the eluent was blown dry with nitrogen. Add 100 μl BSTFA+1% TMCS, derivatize at 60 ℃ for 30 min, blow dry under nitrogen, add 200 μl toluene to dissolve and centrifuge;

6. Take 110 μl for GC/MS analysis.

Caveat

1. before the analysis of the sample to understand the components to be measured and their boiling points, the radio station script can not be fed into the sample, inorganic compounds, strong polar compounds, carboxylic acids, etc. can not be directly into the GC-MS, some high-boiling point, strong polar compounds need to be derivatized before the analysis.

2. The sample must be in organic solvent with low boiling point, such as methanol, acetonitrile, acetone, etc. Direct aqueous injection is not allowed.

3. The solvent and mobile phase for dissolving the sample need to be chromatography grade solvents.

4. Before sample injection, needle filtration or high-speed centrifugation is required before the sample can be analyzed.

Common Problems

1. The interface between gas chromatograph and mass spectrometer has direct import type and jet enrichment type interface.

2. The mass analyzer is the core of the mass spectrometer, the scanning speed of the four-level mass analyzer is fast, about 0.1s, and can be switched freely from the positive ion to the negative ion detection, and dexterous and lightweight, inexpensive; time-of-flight mass analyzer is not the core of the egg is the ion drift tube, which carries out the principle of mass separation is: with the same kinetic energy but different mass of the ions of different speeds of flight, with a pulse to the ion source in the ion instantaneous lead out, accelerated by the accelerating voltage, so that they enter the drift tube with the same kinetic energy. The ions in the ion source are instantly induced, accelerated by the accelerating voltage, so that they enter the drift tube with the same kinetic energy.

Sourced from Drug Chromatography, edited by Ding Li.

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