AutoDilution using Chromeleon 7 CDS software and vial-to-vial dilutions

Significance of the Topic

Wastewater and complex sample matrices often contain analyte concentrations that exceed calibration curve limits. Manual identification, dilution, and reanalysis consume significant time and resources. Automated vial-to-vial dilution with Chromeleon 7 CDS streamlines this process, reduces operator intervention, and improves laboratory throughput in environmental and industrial analysis.

Objectives and Study Overview

This technical note illustrates how to configure and execute AutoDilution within Thermo Fisher Scientific Chromeleon 7 CDS. It covers the setup of undiluted and diluted instrument methods, conditional logic for threshold detection, and automated vial positioning to enable seamless reanalysis of out-of-range samples.

Methodology and Instrumentation

• Chromeleon 7 CDS software with Intelligent Run Control and AutoDilution feature
• Dionex AS-AP autosampler configured for vial-to-vial dilutions
• Dual instrument methods: one for initial (undiluted) injections and one for diluted injections
• Dilution commands implemented as fixed ratio (e.g., 10-fold) or variable ratio based on calculated AutoDilutionRatio in the autosampler script
• System suitability test (SST) cases and conditional Fail Actions for automated method switching and vial positioning

Key Results and Discussion

The AutoDilution workflow automatically flags samples exceeding calibration limits, executes a programmed dilution in an adjacent vial, and re-injects the diluted sample using the secondary method. Two strategies were demonstrated:

• Fixed dilution: a 10× dilution created by drawing 50 µL sample and adding 450 µL diluent
• Variable dilution: dynamic adjustment of sample and diluent volumes to center analyte concentration within the calibration range

The integration of autosampler scripting and SST templates ensures precise liquid handling and reliable concentration control without manual interventions.

Benefits and Practical Applications

• Significant time savings and increased productivity by automating dilution steps
• Minimized human error and consistent sample treatment across large batches
• Flexible configuration for diverse applications such as environmental monitoring, wastewater analysis, and quality control
• Improved data quality through standardized dilution protocols and conditional logic

Future Trends and Opportunities

Advanced applications may include multi-stage automated dilutions for ultra-trace analytes, integration with laboratory information management systems (LIMS), and incorporation of artificial intelligence to optimize dilution ratios based on historical performance. Robotics integration could further enhance throughput and reproducibility.

Conclusion

Chromeleon 7 CDS AutoDilution with Intelligent Run Control provides a robust solution for automatic vial-to-vial sample dilutions. By combining software-driven conditional logic and flexible autosampler scripting, the workflow delivers reliable dilutions, reduces hands-on time, and maintains data integrity for complex analytical tasks.

References

No external literature references were provided in the original document.