Antibiotic Residue Testing

Antibiotic residue detection is an important step to ensure food safety, drug quality, and environmental safety. The following is a detailed analysis of antibiotic residue detection:

1. Detection purpose
The main purpose of antibiotic residue detection is to ensure that food (such as meat, dairy products, aquatic products, etc.), drugs (such as biological products, vaccines, etc.), and the environment do not contain antibiotic residues exceeding the prescribed limit, thereby protecting consumer health and maintaining ecological balance.

2. Detection method
Microbial detection method
Principle: Use the inhibitory effect of antibiotics on microbial growth to detect antibiotic residues.
Advantages: Simple operation, low cost, suitable for batch sample detection.
Disadvantages: The detection cycle is long, and a large amount of culture medium is required, which makes it easy to contaminate.
High-performance liquid chromatography (HPLC)
Principle: According to the different distribution coefficients of different substances between the stationary phase and the mobile phase, the components are separated.
Advantages: With high separation efficiency and high sensitivity, the content of various antibiotics in the sample can be quickly and accurately determined.
Disadvantages: The detection cost is high, a large amount of organic solvents are required, and the operation is complicated.
Mass spectrometry
Principle: By ionizing the compounds in the sample, separation is achieved according to the difference in the mass of different compounds.
Advantages: high sensitivity, high resolution, can accurately determine the content of various antibiotics in the sample, and provide information about the structure of the compound.
Disadvantages: high detection cost, expensive instruments and equipment are required, and the operation is complicated.
Immunoassay
Principle: Use antigen-antibody-specific reaction to detect antibiotic residues.
Advantages: high sensitivity, high specificity, and easy operation.
Disadvantages: high detection cost, expensive antibody reagents are required, and the process of preparing specific antibodies is relatively complicated.
Spectroscopy
Principle: Use the absorption or emission of photon energy by the substance to detect antibiotic residues.
Advantages: easy operation, low cost, suitable for batch sample detection.
Disadvantages: relatively low accuracy and sensitivity, a large amount of sample solution is required, and certain spectral instruments and equipment are required.
Liquid chromatography-tandem mass spectrometry (LC-MS/MS)
Principle: Combine liquid chromatography with mass spectrometry technology to achieve high sensitivity and high-resolution detection.
Advantages: high separation efficiency, fast analysis speed, high sensitivity, easy to eliminate impurity interference, accurate qualitative and quantitative analysis.
Application: Commonly used for the detection of residual antibiotics in vaccines, as well as other scenarios that require high-precision and high-sensitivity detection.
3. Detection steps
Taking the detection of tetracycline antibiotic residues by high-performance liquid chromatography (HPLC) as an example, the detection steps usually include:

Sample processing: Weigh an appropriate amount of sample, chop or homogenize it, add an extraction solvent to extract the antibiotics by oscillation, centrifuge to obtain the supernatant, and purify it through a solid phase extraction column to remove impurities.
Instrument preparation: Use a high-performance liquid chromatograph equipped with an ultraviolet detector (UV) or a fluorescence detector, and select a suitable chromatographic column, mobile phase, flow rate, and detection wavelength.
Injection and detection: Inject the purified sample solution into the chromatographic column through an injector, and record the chromatographic peak area of ​​each antibiotic.
Quantification and result analysis: Use a standard curve to quantify the antibiotic content in the sample, and judge whether it complies with relevant regulations and standards based on the results.
4. Detection standards and regulations
The detection standards and regulations for antibiotic residues may vary from country to country and region to region. In China, methods and standards for the use and residue detection of antibiotics in biological products have been formulated, and there are also regulations on the maximum residue limit of antibiotic residues in food. When testing antibiotic residues, testing agencies should strictly follow relevant standards and regulatory requirements.

V. Precautions
The selection of testing methods should be determined according to the specific sample type, testing purpose, and regulatory requirements.
When testing antibiotic residues, attention should be paid to sample handling and storage conditions to avoid sample contamination or deterioration.
During the testing process, operating procedures and safety requirements should be strictly followed to ensure the accuracy and reliability of the test results.
For samples with abnormal test results or non-compliant samples, re-testing and further analysis should be carried out in a timely manner.
In summary, antibiotic residue testing is an important means to ensure food safety, drug quality, and environmental safety. By selecting appropriate testing methods, following relevant standards and regulatory requirements, and paying attention to various details in the testing process, the accuracy and reliability of the test results can be ensured.