BAC Resolution Control Standard n-P on Rtx®-BAC Plus 1 and Plus 2 Column Set

Significance of the Topic

• Accurate separation of light alcohols and carbonyls is critical for quality control in food, beverage and environmental testing.
• Resolution control standards enable laboratories to verify column performance and method robustness.

Objectives and Study Overview

• Evaluate performance of two capillary columns (Rtx®-BAC Plus 1 and Plus 2) for separating a six-component headspace standard (methanol, acetaldehyde, ethanol, isopropanol, acetone, 1-propanol).
• Demonstrate new resolution control standard (n-P) applicability for routine monitoring of volatile analyte separations.

Methodology and Instrumentation

• Sample Preparation
  • 50 µL of BAC resolution control standard n-P diluted to 1 mL with water in a 20 mL headspace vial.
• Instrumentation
  • Gas chromatograph: Agilent/HP 6890 GC with FID at 240 °C.
  • Headspace autosampler: Tekmar HT3; vial equilibrium at 60 °C for 5 min; loop split injection (50:1).
  • Columns: Rtx®-BAC Plus 1 (30 m × 0.32 mm ID, 1.8 µm) and Plus 2 (30 m × 0.32 mm ID, 0.6 µm), connected via 5 m guard column and Universal “Y” Press-Tight® connector.
  • Carrier gas: helium at constant linear velocity (80 cm/s); headspace vial pressure 30 psi; loop pressure 20 psi.
  • Oven program: 40 °C (3 min hold); injection port 200 °C; transfer line and valve oven 125 °C.

Results and Discussion

• Chromatographic separation
  • All six analytes resolved within 2.4 min on both columns.
  • Rtx®-BAC Plus 1 showed slightly longer retention times but higher resolution for early eluters; Plus 2 delivered faster analysis with comparable baseline separation.
• Resolution metrics
  • Consistent retention times for each analyte (RSD <1% across replicates).
  • Baseline separation achieved for closely eluting pair (acetone/1-propanol).

Benefits and Practical Applications

• Rapid routine analysis of volatiles in quality control labs.
• Standardized resolution control ensures column performance monitoring and method reproducibility.
• Flexibility to choose column based on throughput versus resolution priorities.

Future Trends and Opportunities

• Integration with automated headspace–GC–MS for trace-level detection and identification.
• Development of multi-analyte resolution standards covering broader compound classes.
• Application of retention modeling and predictive analytics to optimize method transfer between labs.

Conclusion

• The BAC resolution control standard n-P effectively verifies column performance on both Rtx®-BAC Plus 1 and Plus 2.
• Method offers fast, reliable separation of key volatile analytes with minimal sample prep.
• Laboratories can adopt this approach to maintain consistent quality control in diverse analytical environments.

References

• Restek Corporation. BAC Resolution Control Standard n-P on Rtx®-BAC Plus 1 and Plus 2 Column Set. Application Note.