Automating the Accurate Transfer of Highly Volatile to Highly Viscous Liquids using a Bench-top Workstation

Význam tématu

The transfer of liquid standards—ranging from highly volatile solvents to viscous fluids—is critical for precise analytical results and calibration. Manual handling can introduce errors, especially with low-boiling or high-viscosity reagents. Automating this process improves throughput, reproducibility, and data quality.

Objectives and Study Overview

This application note evaluates the GERSTEL MPS workstation for automating precise transfers of liquids with diverse volatility and viscosity. Key goals include integrating liquid handling with weight verification, assessing new vial venting tools, and quantifying improvements in accuracy and precision across representative compounds.

Methodology and Instrumentation

Automated transfers were performed with the GERSTEL MultiPurpose Sampler equipped with:

• Balance Option (Sartorius Cubis MSU524S) for gravimetric verification
• Purge Tool Option for maintaining constant vial pressure

Liquid standards (acetonitrile, pentane, Freon 113, 1,1-dichloroethylene) were maintained at controlled temperatures and transferred by syringe. MAESTRO software features such as “Accurate ADD”, viscosity delays, and aliquot corrections were used for optimization.

Main Results and Discussion

• Use of the Purge Tool reduced negative deviations by up to 50 % for volatile liquids.
• Temperature control (20–30 °C) significantly improved transfer accuracy for viscous and volatile compounds.
• Software strategies (Accurate ADD, viscosity delay, two-aliquot transfers with correction factors) yielded precision better than 1 % CV and accuracy within ±3 % of theoretical weight after optimization.
• Custom blended gas standards prepared via optimized liquid transfers showed differences from expected concentrations below ±3.8 % when analyzed by GC-FID.

Benefits and Practical Applications

Automating complex liquid transfers streamlines calibration, standard preparation, and solvent pipetting in GC/MS and LC/MS workflows. Gravimetric feedback and pressure control minimize human error, enhance method robustness, and support QA/QC requirements in industrial and research laboratories.

Future Trends and Possibilities

Integration of advanced sensing (e.g., real-time viscosity measurement), adaptive temperature and pressure control, and machine learning algorithms could further refine automated dosing. Expanding compatibility with a wider spectrum of solvents and reagents will broaden applications in high-throughput analysis and regulated environments.

Conclusion

The GERSTEL MPS combined with the Balance and Purge Tool Options and MAESTRO software features enables highly accurate and reproducible automated transfers of both volatile and viscous liquids. Optimization protocols deliver precision better than 1 % CV and accuracy within a few percent of target weights, enhancing throughput and data integrity.