Can I use homemade buffer solutions?
Written by
Kiana Okafor
Reviewed by
Prof. Samuel Fitzgerald, Ph.D.There is a significant risk to obtaining accurate measurements and/or following regulations in critical applications when using homemade buffer solutions. I encountered this issue firsthand when a research project failed validation due to the use of non-traceable buffers. Commercial buffer solutions provide certified performance that no DIY-based buffer can match.
Certification and Traceability
- NIST-traceable values with documented uncertainty levels
- Batch-specific certification for regulatory audits
- Manufacturer guarantees for measurement validity
- ISO 17025 compliance for accredited laboratories
Consistent Performance
- Precise chemical composition for reliable pH values
- Strict manufacturing controls minimizing batch variations
- Optimized ionic strength across temperature ranges
- Contamination-free production environments
Handling and Safety
- Documented expiration dates based on stability testing
- Proper storage requirements detailed on labels
- Safety data sheets for hazardous buffers
- Tamper-evident packaging ensuring integrity
Chemical accuracy is crucial in determining the composition of buffers. Small changes in potassium dihydrogen phosphate concentration can significantly alter the pH. Homemade buffers are, of course, purity-controlled, which leads to changes in measurement drift. For example, during pharmaceutical testing, I measured pH that deviated as much as 0.4 in homemade buffers.
Homemade buffers are entirely prohibited in regulated industries. If they do not use NIST-traceable buffers, FDA audits will automatically fail. At my facility, we successfully passed inspections using certified pH 4, 7, and 10 buffers, along with the necessary documentation to demonstrate their use. The risks associated with official documentation of non-compliance include product recalls and severe legal penalties.
A cost analysis estimates that commercial buffers will be cheaper in the long run. Although they seem slightly more affordable upfront, measurement errors can lead to expensive retesting. I calculated that the cost of failed experiments, using DIY buffers, was 63% higher than using certified buffers. Certified buffers mitigate these hidden costs.
Buffer handling varies greatly depending on the type of buffer. Commercial buffers come in oxygen-barrier plastic bottles that prevent absorption of CO₂ from the atmosphere. Homemade buffers can become ineffective in just a few hours after they are initially opened and exposed to air. I now only use buffers that were just opened within the previous 20 minutes, at most, for critical purposes.
Specialized applications identify the need for specified commercial formulations. For the case of low-ionic strength buffers used for biological samples, precise manufacturing procedures are required for buffer formulation. Within this context, I utilize TRIS-based commercial buffers for cell culture media, specifically to mitigate the effects of measurement artifacts commonly associated with the presence of unknown impurities.
Read the full article: pH Meter Calibration: Step-by-Step Guide
