Analyze Semivolatiles with Agilent J&W Ultimate Plus Tubing in an Inert Flow Path

Significance of the Topic

Trace-level analysis of semivolatile organic contaminants in environmental samples is critical for monitoring pollutants with diverse chemistries and reactive functional groups. Active sites within the gas chromatograph flow path can degrade or adsorb sensitive analytes, resulting in poor peak shapes, low reproducibility, and reduced sensitivity. Establishing an inert flow path from injector to detector is essential for reliable quantitation of hydroxylated, amino, carbamate, and organophosphate compounds at trace concentrations.

Objectives and Study Overview

This study evaluates the inertness performance of Agilent J&W Ultimate Plus deactivated fused silica restrictor tubing compared to a premium tubing from another supplier. Using a 29-component semivolatile organic analyte checkout mixture, the work aims to demonstrate improvements in peak symmetry, signal response, and reproducibility under identical GC/MS conditions.

Methodology and Instrumentation

A semivolatile checkout standard at 10 ng/µL (29 compounds in dichloromethane) was injected on an Agilent 7890A GC coupled to a 5975C MSD. The GC column was an Agilent J&W DB-UI 8270D Ultra Inert (20 m × 0.18 mm, 0.36 µm). Agilent or competitor restrictor tubing (1.1 m × 0.15 mm) served as the MS interface connection. Sample injections (1 µL) were performed in splitless mode at 300 °C. The oven ramp from 40 °C to 320 °C at 20 °C/min delivered analysis times under 19 minutes. MS settings included full-scan acquisition (m/z 35–400) after a 3 min solvent delay.

Main Results and Discussion

Total ion chromatograms confirmed successful detection of all 29 components at 10 ng on-column with symmetrical peaks and low baseline noise when using Agilent tubing. Expanded views of 2,4-dinitrophenol showed sharp, symmetric peaks and strong signal intensity, indicating minimized surface adsorption. Overlaying chromatograms from Agilent and competitor tubing revealed consistent response enhancements across the analyte range. Normalized response comparisons at 5 ng and 2 ng on-column highlighted up to 150 % signal gain with Ultimate Plus tubing, particularly for organophosphorus and organochlorine pesticides such as mevinphos, terbufos, DDT, and endrin.

Benefits and Practical Applications

• Enhanced inertness yields improved peak shape and quantitative accuracy for reactive semivolatiles.
• Increased sensitivity at trace levels supports lower detection limits and better reproducibility.
• Fast, convenient column changes without venting the MS maintain laboratory throughput.
• Robust performance across a broad range of compound chemistries benefits environmental monitoring and regulatory compliance.

Future Trends and Potential Uses

Ongoing developments may include novel deactivation chemistries for tubing and liners to further reduce active sites. Integration with high-throughput fast-GC and high-resolution mass spectrometry can expand analytical capabilities. Application of inert flow path technology to other challenging analyte classes—such as pharmaceuticals in water or polar pesticide residues—offers additional opportunities.

Conclusion

Agilent J&W Ultimate Plus deactivated fused silica tubing delivers superior inertness compared to a leading premium competitor, providing significant response gains, improved peak symmetry, and reliable trace-level quantitation of semivolatile contaminants. Its use as a GC restrictor for MS ensures robust, reproducible results and supports high-sensitivity environmental analyses.

References

1. Szelewski M Semivolatiles Retention Time Locked Deconvolution Databases for Agilent GC/MSD Systems Agilent Technologies Application Note 5989-5875EN 2008
2. Lynam K Semivolatile Analysis Using an Inertness Performance Tested Agilent J&W DB-5ms Ultra Inert Column Agilent Technologies Application Note 5989-8616EN 2008
3. Lynam K Semivolatile Analysis with Specially Designed Agilent J&W DB-UI 8270D Columns Agilent Technologies Application Note 5991-0250EN 2012
4. Zhao L Broske AD Mao D Vickers A Evaluation of the Ultra Inert Liner Deactivation for Active Compounds by GC Agilent Technologies Technical Overview 5990-7380EN 2011
5. Anon Purged Ultimate Union Agilent Technologies Technical Overview 5991-1114EN 2013
6. Lynam K Agilent Inert Flow Path Enhancements Impact on Semivolatile Analysis Agilent Technologies Application Note 5991-2745EN 2013