Helium ionization gas chromatograph

Helium ionization gas chromatographApplied to high-purity gas analysis standards

GB/T 8979-2008 High Purity Nitrogen

GB/T 4844.3-1995 High Purity Helium

GB/T 7445-1995 Pure Hydrogen, High Purity Hydrogen, Ultra Pure Hydrogen

GB/T 16942-2009 Gas Hydrogen for Electronic Industry

GB/T 16943-2009 Helium gas for electronic industry

These standards specify the analysis methods for trace impurities in high-purity gases, with helium ionization gas chromatography being the main detection tool.

Gas standard for electronic industry

GB/T 14604-2009 Gas Oxygen for Electronic Industry

GB/T 14600-2009 Gases for Electronic Industry - Argon Nitrogen Oxide

GB/T 18994-2003 Gases for Electronic Industry - High Purity Chlorine

These standards apply to the semiconductor and electronic manufacturing industries, requiring the use of helium ionization gas chromatography to detect ppb level impurities

Helium ionization gas chromatographworking principle

Helium as carrier gas and ionization source:

High purity helium gas produces high-energy metastable helium atoms (He *) or helium ions (He ⁺) under high voltage electric field or radioactive source (such as beta rays) excitation.

When the measured gas molecules collide with these high-energy particles, ionization occurs, producing electrons and positive ions, forming an electric current signal.

The signal strength is directly proportional to the gas concentration.

Detection mode:

Pulse Discharge Mode (PDHID): High energy helium plasma is generated through pulse discharge, with high sensitivity and no need for a radioactive source.

Traditional mode: relying on radioactive isotopes (such as ³ H or ⁶ ³ Ni) to excite helium gas, which is now less commonly used.

Core Features

Ultra high sensitivity:

The detection limit can reach ppb level (or even lower), making it particularly suitable for trace gas analysis.

Excellent response to gases such as H ₂, O ₂, N ₂, CO, CO ₂, etc

Wide linear range:

The signal and concentration exhibit a linear relationship across multiple orders of magnitude, making it suitable for the analysis of samples with different concentrations.

generality:

It can detect almost all gases (including inert gases), but has low sensitivity to complex organic compounds.

Main application areas

Environmental monitoring:

Detection of trace pollutants in the atmosphere, such as CO, CH ₄, SF ₆.

Greenhouse gas (CO ₂, N ₂ O) analysis.

Petrochemical industry:

Quantitative analysis of H ₂, O ₂, N ₂, CO and other components in natural gas, refinery gas, and cracking gas.

Impurity detection in high-purity gases such as electronic grade argon and nitrogen.

Semiconductor industry:

Quality control of trace impurities in ultra pure gases (helium, neon, argon).

Research field:

Analysis of Rare Gases (He, Ne, Ar) in Geological Samples.

Real time monitoring of gas products in chemical reactions.

局限性

Dependent on high-purity helium gas:

Helium has high cost and limited resources, requiring strict purification to avoid impurity interference.

Complex maintenance:

The system needs to be highly clean to avoid baseline drift or noise caused by contamination.

The pulse discharge mode requires optimization of parameters such as voltage and flow rate.

Low sensitivity to organic compounds:

Complex organic compounds, such as hydrocarbons, are more suitable for detection using FID or MS.

Helium ionization gas chromatographComparison with other detectors

detectorsensitivityApplicable substancesCarrier gas requirementsfeature

HIDnoble gasHigh purity helium gas must be usedWide linear range, strong universality

TCDlowGeneralAny carrier gasGood stability, but low sensitivity

FIDtallorganic matterHydrogen/AirExcellent response to hydrocarbons

ECDtallElectronegative substances (such as halogens)Nitrogen/ArgonHigh selectivity, used for pesticide and PCB analysis

Precautions

Helium purity: It is recommended to use helium gas with a purity of 99.999% or higher and equip it with a gas purifier.

System leakage: Minor leaks can cause unstable baselines and require regular leak detection.

Column selection: commonly used molecular sieves, PLOT columns, or capillary columns for gas separation