Chrom GC-126N PDD Helium Ionization Gas Chromatograph

Overview

The Chrom GC-126N PDD Helium Ionization Gas Chromatograph is a purpose-built analytical system engineered for the quantitative detection of trace-level impurities—down to sub-ppb concentrations—in ultra-high-purity (UHP) industrial gases and electronic specialty gases. It operates on the principle of pulsed discharge helium ionization detection (PDHID), a highly selective and universally responsive detection mode for permanent gases and light hydrocarbons. Unlike flame ionization (FID) or thermal conductivity (TCD) detectors, PDHID delivers uniform response factors across H₂, O₂, N₂, CO, CO₂, CH₄, Ar, Kr, Xe, Ne, and other inert and reactive species—enabling accurate, calibration-robust quantification without compound-specific correction factors. The system integrates a multi-valve, multi-column architecture with center-cutting and backflush capabilities, eliminating the need for manual column switching or method reconfiguration when analyzing diverse gas matrices—including high-purity nitrogen (GB/T 8979–2008), oxygen (GB/T 14599–2008), helium (GB/T 4844.3–1995), argon (GB/T 4842–2006), hydrogen (GB/T 7445–1995), and electronic-grade silane (GB/T 15909–2009).

Key Features

• Valco-sourced pulsed discharge helium ionization detector (PDHID) with <5 ppb detection limit for H₂, O₂, N₂, CO, CH₄, and CO₂—validated per ISO 10156 and ASTM D1945 methodologies
• Four-valve, five-column center-cutting and backflush configuration using Valco吹扫-type 10-port and 6-port switching valves with continuous purge gas protection to eliminate memory effects and cross-contamination
• Dedicated UHP gas handling architecture: 316 stainless steel tubing, gold-plated zero-dead-volume fittings, HP-2 helium purifier (residual impurities ≤10 ppb), and 2 μm carrier gas filtration
• Modular dual-zone column oven with independent temperature control for parallel optimization of separation and desorption conditions; ±0.1 °C stability over full range (+5 °C to 400 °C)
• Embedded 32-bit processor with USB-based bidirectional instrument control; supports automated valve sequencing, detector zeroing, polarity inversion, and sensitivity scaling via digital parameter input
• Backpressure-regulated injection system with zero-dead-volume sampling valves (four units supplied), designed to prevent atmospheric ingress during high-dilution gas sampling

Sample Compatibility & Compliance

The GC-126N PDD meets the stringent requirements of both industrial gas certification and semiconductor manufacturing environments. It is validated for conformance with Chinese national standards including GB/T 8979–2008 (high-purity N₂), GB/T 14599–2008 (O₂), GB/T 4842–2006 (Ar), and GB/T 16942–2009 through GB/T 21287–2007 (electronic-grade gases). Its hardware and operational design align with ISO/IEC 17025:2017 for testing laboratory competence and supports audit-ready data integrity under FDA 21 CFR Part 11 when paired with Chrom-2010PDD workstation software featuring electronic signatures, audit trails, and user-access controls. All wetted surfaces comply with SEMI F57-0301 for semiconductor process gas analysis systems.

Software & Data Management

The Chrom-2010PDD chromatography data system (CDS) provides full bidirectional control of the GC-126N PDD via USB interface. It implements real-time acquisition at up to 50 Hz with 24-bit A/D resolution (±1 μV), dynamic range of 10⁶, and peak area reproducibility better than 0.06% RSD. The software supports time-programmed valve actuation, automatic baseline subtraction, intelligent peak deconvolution (including shoulder, tailing, and co-eluting peaks), and customizable calibration curves using single-point, multi-point linear, or non-linear regression. Quantitative reports are exportable to CSV and Excel formats; spectral overlays, retention time locking, and method versioning ensure GLP/GMP traceability. Raw data files retain full metadata—including instrument parameters, valve timing logs, and detector operating conditions—for regulatory review.

Applications

• Trace impurity profiling in bulk and cylinder-delivered UHP gases for semiconductor fab supply chains
• Residual moisture, oxygen, and hydrocarbon verification in cryogenic liquid storage and distribution systems
• Quality control of electronic specialty gases (e.g., SiH₄, NF₃, BCl₃, PH₃) per SEMI C37 guidelines
• Validation of helium recovery and purification train performance in medical and research facilities
• Compliance testing for food-grade CO₂ (GB 10621–2006) and pharmaceutical nitrogen (USP )
• Environmental monitoring of greenhouse gas standards (CO₂, CH₄) in calibration laboratories

FAQ

What detection principle does the GC-126N PDD employ?
It utilizes pulsed discharge helium ionization detection (PDHID), generating metastable He* species that ionize analytes with near-uniform response across permanent gases and C1–C2 compounds.
Is the system compliant with FDA 21 CFR Part 11?
Yes—when operated with Chrom-2010PDD CDS configured with audit trail logging, electronic signatures, and role-based access control.
Can it analyze both hydrogen and oxygen in the same run?
Yes—via the integrated center-cutting/backflush sequence using Hayesep Q/R and MS 5A columns, eliminating interference from matrix helium or argon.
What carrier gas purity is required?
Helium ≥99.999% (5.0 grade), with optional inline HP-2 purifier to reduce residual H₂, O₂, N₂, and H₂O to ≤10 ppb.
Does the column oven support simultaneous dual-zone programming?
Yes—the modular furnace design allows independent temperature setpoints and ramp profiles for pre-separation and analytical columns.
Are all fluidic components certified for UHP service?
All valves, fittings, and tubing are Valco-specified 316 stainless steel with electropolished interiors and gold-plated zero-dead-volume connections, rated for 1000 psi operation.