Isocratic HPLC Mobile Phase Recycling Without Analytical Compromise
The pharmaceutical industry is under increasing pressure to adopt sustainable practices. Laboratory solvents and specifically HPLC mobile phase is a prime target for reduction due to its environmental, health, and economic impacts.
A common concern, however, is whether recycling volumes might compromise the integrity of analytical results. This concern, while understandable, is not supported by scientific evidence or technological capabilities.
Recycling the non-peak portion of the HPLC mobile phase—also known as solvent recycling or analyte shaving—is a well-established green chemistry practice.
When done with modern smart instrumentation, it does not affect analytical results.
Here’s why:
- Mobile Phase Is a Carrier, Not a Reactant
In HPLC, the mobile phase serves as a transport medium for analytes through the column. It does not chemically interact with the analytes in a way that would alter their structure or detection. Therefore, recycling the portion of the mobile phase that does not contain analytes (i.e., baseline regions) is safe and logical.
- Peak-Based Diversion Ensures Purity
ReSolve Mobile Phase Recycler uses advanced peak detection algorithm and electronics to monitor the eluent. When peaks are detected (i.e., analyte is present), the flow is diverted to waste. When no peak is present, the flow is diverted back to the solvent reservoir. This ensures:
- Only pure mobile phase is recycled
- No cross-contamination occurs
- Baseline integrity is maintained
- No Impact on Retention Time or Resolution
Since the recycled solvent is chemically identical to fresh solvent it does not alter:
- Mobile phase composition
- Flow rate
- Column pressure
- Analyte retention behavior
Thus, retention times, peak shapes, resolution and reproducibility remain consistent.
- Proven in Routine and Regulated Environments
Many pharmaceutical labs, especially those operating under GMP and GLP, have successfully implemented solvent recycling systems. These systems are validated and show no impact on method performance.
Regulatory bodies such as FDA, EMA, MHRA etc. support method validation based on performance criteria, not solvent volume. HPLC methods need to meet:
- Linearity
- Accuracy
- Precision
- Specificity
- Robustness
…to be considered valid, regardless of the solvent volume used.
This provides flexibility to adopt greener practices without regulatory risk.
- Environmental and Economic Benefits
Recycling the non-peak portion of the mobile phase:
- Dramatically Reduces solvent consumption by up to 90%
- Lowers hazardous waste disposal costs
- Reduces mobile phase preparation time and personnel exposure
- Reduced mobile phase container volumes – no more lifting 5Litre bottles!
- Improves sustainability metrics
✅ Conclusion
Recycling the non-peak portion of the HPLC mobile phase is a safe, validated and sustainable practice that does not compromise analytical results when implemented with a compliant diversion system. It aligns with green chemistry principles and is increasingly adopted in modern pharmaceutical laboratories.
ReSolve is specifically designed for GMP laboratories. It records every injection/chromatogram with the times and volume of each Waste and Recycle event and is fully compliant with FDA 21 CFR part 11 and ALCOA+ requirements.
To learn more, check out the Product page or contact our team at info@antech.ie.