Direct Injection System

The direct injection system – often referred to as liquids module - must be capable of delivering the sample material into the carrier gas stream at controlled and repeatable rate. The carrier gas stream transfers the evaporated liquid sample into the oxidation zone.

A syringe driver or liquid auto sampler controls the dispense speed of a microliter syringe which typically set at 1 μL/s. A constant rate ensures a controlled combustion which prevents the formation of soot.

The direct injection system is typically heated at 500 ℃. The sample evaporates immediately when entering the module, feeding the detector with a continuous combustion flow and resulting in repeatable peak shapes.

The direct injection system is especially recommended when the sample is not viscous and has a boiling point lower than 420 °C.

Applications suitable for direct injection:
• Light Hydrocarbons
• Naphtha
• Fuels
• Chemicals
• High purity solvents
• LPG
• Gas