How does an FID Work?
An FID, or Flame Ionization Detector, is the most common detector paired with gas chromatography instruments for analytical applications. It is used in a number of industries such as in natural gas, pharmaceutical, and petrochemical markets. But how does an FID work?
An FID uses a flame to ionize organic compounds containing carbon. Following separation of the sample in the GC column, each analyte passes through a flame, fuelled by hydrogen and zero air, which ionises the carbon atoms.
Once formed, the ions are collected and measured as they create a current at the detector’s electrodes. The current is produced as the detector collects the charged ions. The current is then converted to an electrical signal in picoamperes (pA) or millivolts (mV).
An inert make-up gas is also often used to ensure that additional gas flow is provided to the sample ions as they move through the detector, which can improve analytical results. When using a make-up gas, it is important that the gas used is inert and contains minimal impurities which could interfere with the sample analysis, risking dampening the signal or increasing the baseline. Although helium can be used for make-up gas, nitrogen is often the more cost-effective option, and can be supplied via a nitrogen gas generator.
Using gas generators for GC-FID
Using a gas generator for GC-FID analysis brings convenience and reliability to the lab. Labs performing analyses such as GC-FID, where multiple gas sources are required saves lab managers and employees the hassle of coordinating gas cylinder orders to ensure the gas supply doesn’t run out mid-analysis. Opting for gas generators for GC-FID can be more cost-effective and is the safest alternative to cylinders, since gas is generated on-demand to meet instrument needs, without storage of large volumes of highly pressurized gas.
Precision Series for GC-FID
Peak Scientific’s Precision series is a dependable gas solution to supply FID for labs, providing hydrogen and zero air to produce the flame and nitrogen for the make-up gas. Precision gas generators produce high purity gases from a compact and stackable system, providing labs with a consistent, and continuous practical solution for FID requirements. For labs requiring nitrogen or hydrogen carrier gas, Precision can provide a complete gas solution for carrier and detector gases.
Bringing convenience and simplicity to the lab, Peak Scientific’s all-new Precision Hydrogen SL generator is the newest solution for GC-FID. Available to order from February 2020, Precision Hydrogen SL is the smallest laboratory-grade H2 generator, offering two flow rates of 100cc and 200cc. With a single button for operation and equipped with advanced fail-safe features, Precision SL is a safer and simpler alternative to hydrogen gas cylinders.
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