Quantitation of trace components in liquid process streams by direct liquid sampling mass spectrometry

Area of Science:

• Analytical Chemistry
• Mass Spectrometry
• Chemical Process Monitoring

Background:

• Traditional trace analysis often relies on chromatographic separation, which can be time-consuming.
• Accurate and rapid quantification of trace impurities is crucial for industrial process control and product quality.

Purpose of the Study:

• To develop and validate a direct liquid sampling interface for electron impact ionization magnetic sector mass spectrometry.
• To enable rapid, sensitive, and robust trace analysis without chromatographic separation.
• To assess the system's performance for both simple and complex industrial samples.

Main Methods:

• Development of a liquid sample introduction interface utilizing Programmable Temperature Vaporizing (PTV) GC injection principles.
• Application of univariate analysis for propanoic acid in acetic acid analysis.
• Implementation of multivariate analysis (partial least squares regression) for complex ester impurity profiling.

Main Results:

• Achieved a detection limit of 16 mg/L for propanoic acid in acetic acid with rapid analysis (30 scans/min).
• Successfully identified and quantified six trace impurities in an ester sample with detection limits of 20-30 mg/kg.
• Demonstrated system robustness and ease of operation over several months with minimal maintenance.

Conclusions:

• The developed direct liquid sampling PTV interface offers a fast and sensitive alternative to conventional GC for trace analysis.
• The system provides accurate results, enabling tighter process control and adherence to product specifications.
• This method is suitable for both routine quality control and complex impurity profiling in industrial settings.