N2O/CO/CO2/CH4 analysis system (TCD/FID) Nexis GC-2030NCCC1 GC-2014NCCC1

Význam tématu

Accurate measurement of nitrous oxide and related gases in ambient air is essential for climate research, industrial emissions monitoring and air quality assessment. The described GC method offers sensitive, simultaneous quantification of N2O, CO, CO2 and CH4, addressing both trace‐level and major gas analysis in a single platform.

Cíle a přehled studie / článku

This application note details a dual‐channel gas chromatograph configured for:

• Trace N2O determination by GC–ECD using Porapak-N and HayeSep-D packed columns.
• Simultaneous analysis of permanent gases (O2, N2, CH4, CO, CO2) with TCD and trace CH4, CO, CO2 with FID after methanization.

The system employs five switching valves, seven packed columns and two sample loops to optimize separation and detection.

Použitá metodika a instrumentace

The analytical setup comprises:

• Gas chromatograph models Nexis GC-2030NCCC1 or GC-2014NCCC1.
• Detectors: one electron capture detector (ECD), one thermal conductivity detector (TCD) and one flame ionization detector (FID) with methanizer.
• Packed columns: Porapak-N (pre-column for C2 backflush), HayeSep-D (N2O separation), Porapak-Q and molecular sieve 13X (CO2 and permanent gas separation), MS-13X (CO/CH4 split).
• Lab Solutions GC workstation software for instrument control and data processing.

Two analytical sequences are described:

• Method-1 uses Porapak-N to separate C2 compounds and MS-13X to resolve air, CH4 and CO; CO2 is directed to TCD.
• Method-2 routes CO and CH4 through MS-13X then methanizer/FID, while CO2 bypasses the molecular sieve to Porapak-Q then FID.

Hlavní výsledky a diskuse

The system achieves low detection limits and broad dynamic ranges:

• N2O: 50 ppb to 100 ppm (ECD).
• CH4, CO, CO2: 1 ppm to 100 ppm (FID after methanizer).
• Permanent gases (CH4, CO, CO2, N2, O2): 0.01 % to up to 20 % (TCD).

Typical chromatograms demonstrate baseline separation of targeted species within 10 minutes. ECD traces show a sharp N2O peak; TCD traces resolve O2, N2, CH4, CO and CO2 sequentially; FID profiles confirm CO and CO2 conversion to CH4 with high sensitivity. The system exhibits good repeatability and stable retention times.

Přínosy a praktické využití metody

Key advantages and applications:

• Single‐system analysis of trace and major atmospheric gases, reducing instrument footprint.
• High sensitivity for N2O with ECD and for hydrocarbons and CO/CO2 via methanizer‐FID.
• Effective removal of O2 to protect methanizer catalyst and prolong its service life.
• Versatile software simplifies sequence programming and data evaluation.
• Suitable for environmental monitoring, industrial emissions testing and quality control in laboratories.

Budoucí trendy a možnosti využití

Emerging directions include:

• Integration of real‐time sampling and automated calibration for continuous monitoring.
• Development of more inert column materials to further lower detection limits and reduce bleed.
• Coupling with mass spectrometry for enhanced selectivity and identification of unknowns.
• Miniaturized or portable GC configurations for field deployment.
• Improved catalyst formulations to extend methanizer lifetime and enable wider analyte scope.

Závěr

The described GC method provides a robust, sensitive and versatile solution for simultaneous analysis of N2O, CO, CO2 and CH4 in atmospheric and industrial gas samples. Its multi‐column, multi‐detector configuration achieves rapid separations with excellent reproducibility, making it a powerful tool for both research and routine monitoring.

Reference

• Shimadzu Corporation. System Gas Chromatograph N2O/CO/CO2/CH4 Analysis System (TCD/FID), First Edition, November 2017.