Lower Detection Limits and Quantitate with Confidence with Breakthrough Ultra Inert Technology

Significance of Ultra Inert Technology

Gas chromatography performance depends on inert flow paths to avoid analyte interactions that cause tailing, loss of sensitivity and reproducibility problems. Active sites on liners, columns and MS sources lead to degraded peak shapes, poor linearity at trace levels and unstable baselines. Developing robust ultra inert deactivation strategies addresses these challenges and supports reliable low-level quantitative analysis across diverse applications.

Objectives and Study Overview

This work aims to define the concept of chromatographic inertness, identify critical components of the GC flow path, and demonstrate the performance of Ultra Inert liners and columns under rigorous testing conditions. Key goals included optimizing liner deactivation protocols, comparing deactivation chemistries for columns, evaluating breakdown of labile compounds, and verifying lot-to-lot reproducibility through standardized quality control.

Methodology and Instrumentation

Comprehensive inertness evaluation involved deactivation of glass liners using acid leaching followed by silylation with TMCS or DMCS. Ultra Inert columns utilized proprietary polymeric deactivation to blanket silanols. Performance was benchmarked using demanding test mixes (organic acids, bases, alcohols, phosphate esters) at low temperatures. Applications were demonstrated on Agilent systems configured as follows:

• GC/MSD: Agilent 6890N with 5975B MSD, transfer line 290 °C, source 300 °C.
• Sampler: Agilent 7683B/7683 ALS, split/splitless injection with deactivated single taper liners (5183-4647).
• Columns: DB-5ms Ultra Inert (30 m × 0.25 mm × 0.25 µm, 122-5532UI) and 15 m variant (122-5512UI).
• Detectors: FID at 325 °C, carrier gases helium or hydrogen constant flow.

Results and Discussion

Ultra Inert liners maintained <20 % breakdown of Endrin after 100 injections, significantly outperforming competitive liners which exhibited up to 34 % degradation. Trace recovery of 2,4-dinitrophenol over 2–80 ng on column showed relative standard deviations below 15 % on Ultra Inert liners versus >20 % for others. Ultra Inert columns delivered sharp peaks for strong probes, preserving selectivity identical to standard DB-5ms phases without method redevelopment.

Benefits and Practical Applications

• Enhanced sensitivity and lower detection limits for active analytes (e.g., phenols, amines, semivolatiles).
• Extended maintenance intervals and consistent baseline performance for high-throughput laboratories.
• Reliable quantitation in environmental semivolatile analysis, pesticide residue screening, PAHs, PBDEs, and forensic drug testing.
• Lot-to-lot reproducibility assured through quality control certification with trace acidic and basic probes.

Future Trends and Opportunities

Further developments may focus on integrating inert coatings within micro-fabricated flow paths, extending ultra inert surfaces to low-thermal mass systems and two-dimensional GC. Advances in non-siloxane stationary phases and MS ion source inertness will enable even more demanding trace analyses in emerging fields such as metabolomics and nanoparticle characterization. Automated liner deactivation and smart diagnostics promise to streamline workflow in regulated environments.

Conclusions

Ultra Inert technology demonstrates substantial improvements in peak shape, trace-level recovery and durability across GC flow path components. Proprietary liner and column deactivation chemistries ensure consistent inertness, facilitating confident quantitation of active and labile compounds. This approach supports robust, high-throughput analytical workflows without sacrificing selectivity or requiring method modifications.