Detection of penicillin G in milk using a conductimetric method

Area of Science:

• Food safety and analytical chemistry.
• Microbiology and biosensing.

Background:

• Penicillin G is a common antibiotic used in dairy farming.
• Accurate detection of penicillin residues in milk is crucial for public health and regulatory compliance.
• Existing methods for penicillin detection may lack sensitivity or require complex procedures.

Purpose of the Study:

• To develop a highly sensitive and automated method for detecting penicillin G in milk.
• To establish the detection limit and quantitative range of the new method.
• To compare the sensitivity of the new method with existing techniques.

Main Methods:

• Utilized conductance measurement for real-time monitoring of bacterial growth inhibition.
• Employed Bacillus stearothermophilus ATCC 10149 as the indicator microorganism.
• Used a microbiological analyzer to continuously measure conductance changes at 55°C in PM indicator agar.

Main Results:

• Achieved a detection limit of 0.00016 IU/ml for penicillin G.
• Demonstrated a detection time of approximately 3.4 hours.
• Identified a quantitative analysis range of 0.00016 to 0.00062 IU/ml.
• The conductimetric method showed approximately 30-fold higher sensitivity compared to current methods.
• The system allows for simultaneous analysis of 120 or 240 samples, highlighting its automation and high-throughput capabilities.

Conclusions:

• The developed conductimetric method offers a highly sensitive, automated, and efficient approach for penicillin G detection in milk.
• This method significantly surpasses the sensitivity of existing techniques, improving the safety and quality of milk products.
• The automated, simultaneous analysis capability makes it suitable for high-throughput screening in food safety laboratories.