The Benefits of Automatic Melting and Dropping Point Measurement

Automation That Transforms Thermal Analysis

Determining melting and dropping points is a critical step across industries such as pharmaceuticals and fine chemicals, where the purity and quality of raw materials and final products must be assured. Traditionally, these measurements were carried out manually, requiring constant operator attention and relying on subjective human observation. This approach not only consumed significant time but also introduced the risk of variability and error.

Today, modern instrumentation has transformed this process. Automatic Melting Point Excellence and Dropping Point Excellence systems from METTLER TOLEDO eliminate operator subjectivity, increase throughput, and ensure consistent, reliable results, all while supporting compliance with stringent regulatory standards.

Figure 1. Automating Melting Point measurement provides fast and accurate results to your laboratory.

Figure 1. Sample before (left) and after (right) melting event.

Limitations of Manual Observation

In manual melting and dropping point analysis, each measurement can take 10 minutes to more than an hour, demanding full operator engagement. The user must watch the sample continuously through a magnifying lens to identify the exact endpoint. Missing this critical moment means repeating the test. In addition, results depend heavily on the operator’s skill, concentration, and experience, making them highly variable.

The Melting Point Excellence and Dropping Point Excellence instruments from METTLER TOLEDO address these challenges with automated detection of thermal events. Once samples are prepared and inserted, the instrument completes the measurement independently. For melting point determination, the system uses the red-light transmission principle: initially, no red light passes through the solid sample. As melting occurs, light transmission increases until a stable level is reached, precisely indicating the melting point.

Figure 2. Sample before (left) and after (right) melting event.

For dropping point determination, automation uses video detection. The instrument continuously monitors the sample inside the furnace, frame by frame, and captures the exact moment the first drop falls from the cup. This ensures objective and accurate results every time.

In modern laboratories, where the number of samples continues to rise, automatic detection allows users to start measurements and move on to other tasks while the instrument runs independently. Afterward, users can review the recorded video at different playback speeds to verify correct capillary preparation for melting points or to confirm that drops behaved as expected without decomposition.

Increased Efficiency Through Replicates

Melting and dropping point measurements are often required by Pharmacopeia, ASTM, and other regulatory organizations, which typically recommend replicate testing to ensure statistical reliability. The Melting Point Excellence instrument supports simultaneous measurement of up to six replicates, automatically calculating mean values and standard deviation.

Users can also mark outliers, which are excluded from the statistics and recalculated automatically. For extended data evaluation, LabX™ Software (compatible with MP70, MP80, and MP90) provides comprehensive statistical tools.

At the same time, the Dropping Point instrument enables two replicates to be measured in parallel. The system then calculates the mean and the difference between the two samples, delivering accurate and compliant results.

Figure 3. Statistics of the results.

The Melting Point instrument integrates seamlessly with LabX Software, ensuring full compliance with requirements such as 21 CFR Part 11 and EU Annex 11. LabX centralizes all measurement results in one secure database, where users can review melting curves and video recordings at any time. Data protection features prevent modifications or deletions, guaranteeing both integrity and traceability of all measurement records.

Figure 4. Results in LabX Software.

Automation not only increases throughput but also enhances safety and sustainability. A clear example is boiling point determination. Traditional manual methods rely on distillation, which requires large sample volumes and carries safety risks, in some cases even the potential for explosions when handling volatile organic solvents.

By contrast, the MP80 instrument uses just 100 µL of solvent for boiling point analysis, significantly reducing hazards at the workstation. Smaller sample volumes also mean less chemical waste, supporting safer and more environmentally sustainable operations.

Automatic melting and dropping point measurement systems represent a major advance for analytical laboratories across many industries. By replacing subjective visual observation with automated detection, they improve accuracy and reproducibility. By supporting multi-sample testing, they increase efficiency. And with LabX integration, they ensure compliance and data integrity.

At the same time, automation improves laboratory safety and sustainability, lowering chemical risks and reducing waste. These benefits together result in more reliable quality control, streamlined workflows, and safer laboratory environments. For laboratories aiming to meet both operational excellence and regulatory confidence, automation is now essential.

Watch the Melting Point Excellence System in Action

See how METTLER TOLEDO’s Melting Point Excellence portfolio simplifies thermal analysis with fully automated determination of melting point, melting range, boiling point, cloud point, and slip melting point. From intuitive sample preparation to one-click measurement and high-resolution video documentation, the system is designed to maximize accuracy while saving valuable operator time.

For more information, visit:

www.mt.com/Melting-Point

Ewa Ziółkowska

Ewa Ziółkowska is a Product Manager at METTLER TOLEDO, specializing in Physical Values.

With a degree in Biotechnology Engineering and over five years of experience spanning customer support, product management, and application development, Ewa collaborates with cross-functional teams to refine analytical solutions, ensuring they address evolving market needs.