Once the menu is open you can move between options with the arrow keys and select an option with the enter or space keys. Typeahead search is also available.
Go to Home Page

Thermal Conductivity Detector (TCD)

Thermal conductivity detector (TCD) is a technique used to analyse inorganic gases and small hydrocarbon molecules.

Thermal Conductivity Detector (TCD) is a detector used in gas chromatography (GC) to analyse inorganic gases (such as argon, nitrogen, hydrogen, carbon dioxide) and small hydrocarbon molecules. The TCD compares the thermal conductivity of two gas flows, the pure carrier (reference) gas and the sample. Changes in the temperature of the electrically-heated wires in the detector are affected by the thermal conductivity of the gas that flows around them. The changes in this thermal conductivity are sensed as a change in electrical resistance and are measured.

As commonly used with other GC techniques, a carrier gas is required with low water and oxygen impurities, since water and oxygen can interact with the stationary phase and cause significant problems such as high baseline noise and column bleed in the output gas chromatogram that both reduce the analyser sensitivity and decrease column lifetime. In addition, oxygen and water impurities in the detector gas can affect the TCD as they can cause oxidation of the detector wires. 

Air Products' Gases Used in TCD Analysis

Helium BIP® Technology

Unrivalled gas purity specification, less than 10 ppb oxygen, and less than 20 ppb moisture

Hydrogen BIP® Technology

Unrivalled gas purity specification, less than 100 ppb oxygen, and less than 20 ppb moisture

Nitrogen BIP® Technology

Unrivalled gas purity specification, 10 ppb oxygen, 20 ppb moisture

Argon BIP® Technology

Unrivalled gas purity specification, 10 ppb oxygen, 20 ppb moisture

Buy Online

Available to existing customers via MyAirProducts℠

Ask the Expert

Trish Lees

Business Development Specialist

"What are the critical impurities in the Carrier Gas for Thermal Conductivity Detection (TCD)?"
Oxygen and Water are critical impurtiies because they can permanently damage the wires in the detector by oxidation, which causes reduced sensitivity and negative peaks.

Questions? We've got answers.

Contact Us

Ready to order?

BUY NOW

RESOURCE CENTER