860 KF Thermoprep

Significance of the topic

The determination of moisture content in solid and liquid samples is crucial in many fields including pharmaceuticals, food analysis, polymers and petrochemicals. The 860 KF Thermoprep enables efficient thermal extraction of bound water, automating sample preparation and improving reproducibility in Karl Fischer titration. By minimizing manual handling and providing controlled heating and gas flow, it helps laboratories reduce errors, increase throughput and meet stringent quality requirements.

Study objectives and overview

This manual presents the design, setup, operation and maintenance of the 860 KF Thermoprep. The primary objectives are to describe: the instrument components; safe installation and commissioning; operational controls; method parameters; sample conditioning; blank and sample determinations; troubleshooting; and technical specifications.

Methodology and instrumentation

The 860 KF Thermoprep couples a heated oven module with a carrier gas flow to release moisture from samples into a Karl Fischer titration cell for coulometric or volumetric analysis. Key steps include:

• Assembly and installation: Mount the support rod, sample holder and sealing needles, install heating tubing and dust filter, attach drying flasks filled with molecular sieve, and connect an external gas source if required.
• Power-up and configuration: Switch on the unit, select one of two target temperatures, set gas flow rate and source (built-in pump or external valve), and optionally lock the keypad to prevent accidental changes.
• System conditioning: Preheat the oven to the working temperature, insert a sealed blank vial, and switch on the gas flow to purge tubing and titration cell of residual moisture.
• Blank and sample determinations: Perform three to five blank measurements using empty sealed vials to establish background moisture. Then weigh, seal and analyze samples under identical temperature and flow conditions. Use predefined stop criteria (drift limit and time) on the KF titrator.

Main results and discussion

The instrument delivers stable oven temperature control within ±3 °C over a 50–250 °C range and gas flow accuracy across 10–150 mL/min. Heating rates of up to 15 °C/min and cool-down rates of 9 °C/min ensure rapid conditioning. Stainless-steel sample vials with PTFE-coated septa provide hermetic sealing and resist thermal degradation. Modular design allows adaptation to various vial sizes, gases and titration cells.

Benefits and practical applications

The 860 KF Thermoprep offers:

• Minimal sample preparation by using prefilled, sealed headspace vials, reducing exposure and contamination risks.
• Improved accuracy and reproducibility of moisture determinations for difficult matrices.
• Safe handling of flammable or oxygen-sensitive samples through inert gas option and integrated dust filtration.
• Enhanced laboratory efficiency via automated heating, gas control and method parameter storage.

Future trends and potential applications

Advances may include integration with robotic sample loaders, direct LIMS connectivity, miniaturized headspace vials for trace moisture, coupling with GC or IR detectors for volatile by-product analysis, and cloud-based monitoring of system performance and preventive maintenance.

Conclusion

The 860 KF Thermoprep streamlines thermal Karl Fischer water determinations, combining precise temperature control, reliable gas flow and flexible configuration. It reduces manual steps, enhances data quality and supports a wide range of sample types in regulated analytical environments.

Reference

860 KF Thermoprep Manual, Metrohm AG, Document No. 8.860.8003EN, March 2020
Hydranal® Manual, Riedel-de Haën
P. Brüttel & R. Schlink, Water Determination by Karl Fischer Titration Monograph, Metrohm 2006