Cooled Injection System - CIS 6 - Specifications

Importance of Topic

The development of cooled injector technology plays a pivotal role in modern gas chromatography by enabling efficient trapping and focusing of volatile and semi-volatile compounds. Controlling the injection temperature below ambient conditions reduces analyte loss, improves peak shape, and enhances sensitivity, which are critical for trace analysis in environmental, food, and forensic applications.

Study Objectives and Overview

This document provides a comprehensive specification and functional overview of the GERSTEL Cooled Injection System 6 (CIS 6). Objectives include:

• Detailing temperature control and cooling options
• Defining operational modes and automation features
• Summarizing compatibility with Agilent GC platforms and autosamplers

Applied Methodology

The CIS 6 operates as a programmable temperature vaporizing (PTV) inlet featuring dynamic temperature programming and multiple injection modes. Core methodological features include:

• Temperature programming from –180 °C to 650 °C with heating rates up to 20 °C/s
• Cooling options via liquid nitrogen (down to –180 °C), liquid CO₂ (–70 °C), cryostatic or Peltier systems (+10 °C minimum)
• Injection modes: split/splitless, solvent venting, on-column, large-volume, and cryo-trapping
• Automated liner exchange via the ALEX module in conjunction with the GERSTEL MPS 2 autosampler

Applied Instrumentation

The CIS 6 integrates with Agilent 6850, 6890, and 7890 GC systems and is controlled by the GERSTEL Controller C506 under GERSTEL MAESTRO or Agilent ChemStation software. Key hardware components include:

• Agilent electronic pneumatic control (0–100 psi; 0–1000 mL/min He or H₂; 0–200 mL/min N₂)
• Septumless sampling head (SLH) with Kalrez® sealing
• Quartz inlet liners (3×2×71 mm) in straight or baffled designs
• Interfaces: sub-D connectors for cryo/ pneumatic valves, Ethernet/LAN, RS-232, USB ready
• Compatibility with GERSTEL MPS 2 autosamplers and all standard Agilent sample introduction systems

Main Results and Discussion

Specifications demonstrate that the CIS 6 delivers rapid temperature transitions, broad injection versatility, and reliable automation. The combination of sub-ambient trapping and high-temperature back-flushing addresses carryover and matrix effects. Dimensions (39×13.5×31 cm) and weight (~15 kg) allow seamless retrofitting. Operational stability over a wide environmental range (15–35 °C, 50–60 % RH) ensures robust performance.

Benefits and Practical Applications

The CIS 6 system enhances throughput and reproducibility in trace analysis by:

• Reducing analyte discrimination and thermal degradation
• Allowing large-volume injections without excessive peak broadening
• Minimizing maintenance with septumless design and automated liner exchange

Applications span environmental pollutant monitoring, flavor and fragrance analysis, and forensic toxicology.

Future Trends and Potential Applications

Emerging directions include integration with multi-dimensional GC techniques, advanced Peltier-based cooling to reduce cryogen consumption, real-time AI-driven method optimization, and enhanced coupling with high-resolution mass spectrometry for complex matrix characterization.

Conclusion

The GERSTEL CIS 6 cooled injector offers a versatile platform for precision temperature control, broad injection modes, and full automation. Its robust specifications and compatibility with leading GC systems make it a valuable tool for advanced analytical laboratories.

References

No references cited in the source document.