Method name:

Determination of chlortetracycline hydrochloride—high-performance liquid chromatography

Application scope:

This method uses high-efficiency liquid chromatography Liquid chromatography was used to determine the content of chlortetracycline hydrochloride (C22H23ClN2O8·HCl).

This method is suitable for chlortetracycline hydrochloride.

Method principle:

The test sample is made into a 0.01mol/L hydrochloric acid solution, enters the high-performance liquid chromatograph for chromatographic separation, and uses an ultraviolet absorption detector to detect at a wavelength of 370nm. Absorption value of chlortetracycline hydrochloride and calculate its content.

Reagents:

1. 0.1mol/L ammonium oxalate solution

2. Dimethylformamide

3. 0.2mol /L ammonium dihydrogen phosphate solution

4. Ammonia test solution

5. 0.01mol/L hydrochloric acid solution

Instruments and equipment:

1. Instrument

1.1 High Performance Liquid Chromatograph

1.2 Chromatographic Column

Octadecylsilane bonded silica gel is the filler (pH value adaptable range Should be greater than 8.0) The separation between epitropic chlortetracycline and tetracycline, and tetracycline and chlortetracycline should meet the requirements.

1.3 UV absorption detector

2. Chromatographic conditions

2.1 Mobile phase: 0.1mol/L ammonium oxalate solution, 0.2mol/L dimethylformamide Ammonium dihydrogen phosphate solution = 68 27 5, adjust the pH value to 8.3 with ammonia test solution.

2.2 Detection wavelength: 370nm

2.3 Column temperature: 35℃

Sample preparation:

1. Weigh the sample

Precisely weigh 25mg of this product and place it in a 50mL volumetric flask.

2. Preparation of reference solution

Precisely weigh 25mg, add 0.01mol/L hydrochloric acid solution to dissolve and make a solution containing 0.5mg per 1mL, shake well to get .

3. Preparation of test solution

Add 0.01mol/L hydrochloric acid solution to dissolve the test solution and dilute to the mark, shake well, and it is ready.

Note: "Precision weighing" means that the weighing should be accurate to one thousandth of the weight taken. "Precision measuring" means that the accuracy of measuring a volume should comply with the accuracy requirements for pipettes of that volume in national standards.

Operation steps:

Precisely pipette 20 μL each of the above reference solution and the test solution, inject them into the high-performance liquid chromatograph, and use a UV absorption detector to measure gold at a wavelength of 370 nm. The absorption value of mycin was calculated to calculate its content.

References:

Pharmacopoeia of the People's Republic of China and the People's Republic of China, compiled by the National Pharmacopoeia Commission, Chemical Industry Press, 2005 edition, Part 2, p.539.