PC-controlled dosing and liquid handling

Significance of the Topic

The accurate and reproducible dosing of liquids is vital in regulated analytical environments and in the synthesis of sensitive compounds. Automation enhances safety, efficiency, and compliance when handling toxic, corrosive or air-sensitive reagents.

Objectives and Overview

This study examines PC-controlled piston buret dosing systems, focusing on their role in:

• Preparation of demanding standard solutions under GLP/GMP conditions
• Synthesis of moisture- and oxygen-sensitive metal–organic compounds
• Automation of sample preparation workflows for pharmaceutical analysis

Methodology and Used Instrumentation

The core technology is an inverted piston buret design with a ceramic disk offering low dead volume and leak protection. Key features include:

• 800 Dosino dosing units allowing precise low-flow delivery (0.1–2 mL/min)
• Integration with 846 Dosing Interface and 840 Touch Control for workflow customization
• tiamo™ laboratory automation software for parallel operation
• Robotic Filtration Soliprep systems and 815 Robotic Filtration for HPLC sample preparation

Main Results and Discussion

Automated dosing demonstrated improved reproducibility over manual pipetting and gravimetric methods, particularly at low rates and during long-duration additions. The system's portability and flexibility facilitate transfer between synthesis setups, and customized user interfaces reduce training requirements. In application to paracetamol, caffeine, and propyphenazon determinations, end-to-end automation ensured consistent sample processing and data integrity.

Benefits and Practical Applications

Key advantages and uses include:

• Enhanced safety when working with aggressive or toxic reagents
• Reduced manual labor and human error in standard and sample preparation
• High precision in quantitative dosing supporting QA/QC requirements
• Versatility across synthetic chemistry, pharmaceutical analysis, and material characterization

Future Trends and Opportunities

Emerging directions involve deeper integration with robotic sample processors, AI-driven process control for self-optimizing protocols, miniaturization for microfluidic applications, and expanded software capabilities for high-throughput workflows.

Conclusion

The 800 Dosino system, combined with modern interfaces and automation software, provides a robust platform for precise liquid handling in both analytical and synthesis laboratories. Its adaptability and documentation features support compliance and reproducibility across diverse applications.

References

1. van der Heijden E., Steinbach A. Automated preparation of surrogate mixtures for the determination of octane and cetane numbers. Pittcon 2008.
2. van der Heijden E., Krebs P. Probenvorbereitung im analytisch-chemischen Labor. GIT Labor-Fachzeitschrift, 52:11–13 (2008).