The synthesis of amantadine begins with halogenation of adamantane and bromine, and then the intermediate products react with acetonitrile in sulfuric acid to get amide. After base catalyzed hydrolysis, amantadine can be got. Amantadine can be used for the prevention and early treatment of type A-influenza in Asian. Combined with antibiotics, it’s useful to the treatment of septicemia and viral pneumonia, and it is effective to bring down a fever. It is also effective against quiver paralysis, thus it can be used for the treatment of parkinsonism. Based on its pharmacological action, amantadine is mainly used for the prevention and early treatment of chicken or swine flu, and the prevention of swine transmissible gastroenteritis in China.
In consideration of the residue, amantadine has been forbidden from prevention and treatment of viral disease caused by pathogenic microorganisms such as highly pathogenic avian influenza. There is no report before about the residual quantity of amantadine in animal derived food in China, and no national standard or industrial standard has been made before, even certain request to residues or detection method has not been ever raised internationally.
This study developed new method to quantify residues of amantadine in animal derived food using methanol-1%trichloroacetic acid extraction, Cleanert PCX solid phase extraction, and LC-MS/MS technology.
Table 1 Information of 1-Aminoadamantane
Weigh accurately 2 g (accurate to 0.01 g) sample in 50mL centrifuge tube, and added 10 mL methanol 1% trichloroacetic acid (1:1,v/v) mixture in it, swirl 30 s, then ultrasound for 30 min, centrifuge for 10min at 8000 r/min speed. Got the supernate for further filtration, then transfered it using syringe into a sample tube of Qdaura SPE Workstation, and Cleanert PCX SPE cartridge was placed into the tube as well waiting for purify.
Set the program of Qdaura fully automated SPE instrument as below: activate the column using 3mL methanol and 3mL water in sequence, after loading 5mL sample, wash it using 3mL 2% hydrochloric acid, and 3mL methanol in turn. After blow-drying the column in air, eluted the sample using 5mL solution mixed with ammonia, methanol, and isopropyl alcohol (5+80+15, v/v/v), and collected the eluent. All the programs above were operated at the flow rate 1mL/min.
Put the collection tube in a water baths at 50 °C, and dried it in nitrogen. Followed by filtration (0.22 μm), it was dissolved in 1mL solution mixed with methanol, water, and formic acid (10+90+0.1, v/v/v), and then detected it using LC-MS/MS.
Column: Venusil ASB C18, 2.1×150 mm, 3 μm, 150 Å;
Flow Rate: 200 μL/min;
Column Temperature: 30 °C;
Injection Volume: 5 μL;
Ionization mode: ESI in positive mode;
Detection mode: multiple – reaction monitoring (MRM);
Ion source temperature: 550 °C, Curtian Gas: 10, Ion Source Gas 1: 70, Ion Source Gas 2:75;
Table 2 Mobile phase conditions of HPLC chromatography
Table 3 Mass spectrum parameters
Results and Discussion
Table 3 Linearity and detection limit