Analysis of water based products (Chilli Jam, Whiskey, Toothpaste and Chocolate using Entech 7150 Preconcentrator

Significance of the Topic

Water-based products such as chilli jam, whiskey, toothpaste and chocolate pose analytical challenges due to high moisture content, which can degrade GC performance and obscure trace analytes. Efficient water removal and analyte enrichment are essential for reliable quality control and flavor profiling.

Study Objectives and Overview

This study evaluates an automated large-volume headspace preconcentration approach using the Entech 7150 preconcentrator coupled with a 7500 autosampler and GC/MS. The aim was to demonstrate quantitative recovery of volatile and semivolatile compounds in aqueous matrices and to verify method repeatability with duplicate samples and blank controls.

Methodology

Samples (2–10 g solids or 5 ml liquids) were placed in 50 cc headspace vials and equilibrated at 50 °C for 15 minutes. A 100 cc headspace volume was drawn sequentially through:

• Active SPME trap (PDMS coating, 3 m × 0.53 mm) at 30 °C to retain semivolatiles while allowing volatiles and water to pass
• Cold dehydration trap at –30 °C to crystallize and remove residual water
• Cold Tenax trap to capture volatile components with carbon chain lengths <10

After water removal, thermal desorption of the Tenax trap at 200 °C refocused volatiles onto the Active SPME trap (cooled to –60 °C). Finally, the SPME trap was heated to release all analytes onto a DB-WAX column (60 m × 0.32 mm × 0.5 µm) under a temperature program of 40 °C to 240 °C at 1.5 ml/min.

Instrumentation

Entech 7150 Preconcentrator (three-trap configuration)
7500 Autosampler
Agilent GC/MS system
DB-WAX capillary column (60 m × 0.32 mm × 0.5 µm)

Results and Discussion

Total ion chromatogram (TIC) comparisons of duplicate samples and blanks demonstrated effective water removal and clear separation of target analytes:

• Whiskey: Consistent volatile fingerprint with minimal baseline interference
• Chilli jam: Detection of hexanoic acid, correlating with pepper aroma
• Toothpaste: Identification of flavor additives and residual antimicrobial agents
• Chocolate: Presence of tetramethylpyrazine, an artifact of cocoa roasting

The sequential trap configuration prevented water breakthrough and ensured quantitative capture and release of both volatile and semivolatile compounds.

Practical Applications and Benefits

• Fully automated, no-prep analysis of high-moisture matrices
• Enhanced sensitivity for trace-level aroma profiling
• Reduced GC maintenance by efficient water elimination
• High throughput with reproducible sample handling

Future Trends and Opportunities

• Application to additional food, beverage and pharmaceutical matrices
• Development of selective trap coatings for targeted analyte classes
• Integration with real-time data analysis and AI-driven quality assessment
• Portable preconcentration modules for on-site monitoring

Conclusion

The Entech 7150 preconcentrator with active SPME and dehydration traps offers a robust solution for headspace analysis of water-rich products. It delivers reliable trace-level detection while protecting GC systems from water damage, supporting quality assurance and flavor profiling workflows.

References

No external literature references were specified in the source document.