885 Compact Oven Sample Changer

Importance of the Topic

The determination of water content in materials is a critical parameter across pharmaceuticals, food, polymers and petrochemicals. Thermal sample preparation combined with Karl Fischer titration enables accurate moisture analysis in samples that are insoluble or reactive with titrants. Automation of this process improves throughput, reduces operator error and prevents cross-contamination.

Objectives and Study Overview

This application note introduces the 885 Compact Oven Sample Changer as a solution for automated thermal sample preparation in Karl Fischer titration. Key aims include demonstrating its performance over a wide temperature range, evaluating ease of use and showcasing compatibility with various KF titrators.

Methodology and Procedure

The oven method involves sealing weighed samples in vials, heating them up to 250 °C and transporting the released moisture via dry carrier gas into a titration cell. A dual-needle system pierces the vial septum for simultaneous gas inlet and vapor extraction. This approach prevents direct contact between sample and reagent, eliminating memory effects.

Used Instrumentation

• 885 Compact Oven Sample Changer with 18-position rack and temperature control from 50 to 250 °C
• Dry carrier gas supply (10–150 mL/min)
• Compatible stand-alone Karl Fischer titrators (e.g., Titrando series 851, 852, 890, 915, 917, Eco Coulometer)
• Screw-cap vials with septa (8 mL)

Main Results and Discussion

The 885 Compact Oven Sample Changer achieves stable heating rates of approximately 15 °C/min and cooling rates of 9 °C/min. Its compact footprint and integrated keypad control streamline operation. Automated sample sequencing reduces manual intervention, and balance integration allows automatic weight capture. Reusable vials cut consumable costs, while hermetic sealing ensures reproducible moisture transfer.

Benefits and Practical Applications

• Automation enhances laboratory productivity and consistency
• Thermal pretreatment suits a wide range of challenging matrices
• Minimal carryover due to physical separation of sample and reagent
• Flexible integration with existing KF titration systems
• Cost savings from reusable vials and reduced cleaning downtime

Future Trends and Potential Applications

Advances may include integration with robotic sample handlers, real-time data analytics for dynamic temperature profiling and connectivity to laboratory information management systems (LIMS). Miniaturized ovens and microfluidic KF cells could enable ultra-low-volume moisture determination, while AI-driven process optimization may further improve accuracy and throughput.

Conclusion

The 885 Compact Oven Sample Changer offers a robust and user-friendly platform for automated thermal sample preparation in Karl Fischer titration. Its small footprint, flexible temperature control and seamless integration with various titrators make it a valuable tool for high-precision moisture analysis in demanding applications.