An overview of GC Zero Air Generator

An overview of GC Zero Air Generator

When we talk about the GC zero air generator, it is necessary to understand what is zero air first. Zero Air is the air out of which we have removed hydrocarbons via a process of oxidative catalysis. This air contains negligible or less than 0.1 parts per million (PPM) of total hydrocarbons.

Zero air is basically the mixture of nitrogen and oxygen and is used in the laboratory applications where hydrocarbons have a negative effect on the process. Zero air is required in gas chromatography as it supports flame for FIDs (Flame Ionisation Detectors) and FPDs (Flame Photometric Detectors).

Zero air is usually supplied in two ways, either by pressurized gas cylinder or by a gas generator.

Out of these, gas generators are preferred as they are more efficient, modern, convenient and economic for laboratory use and these are known as GC zero air generator . These generators ensure 24 hour supply of gas at the push of a button. It saves time as there is no need to order and change the cylinder s repeatedly. These are safer means of production of gas as there is no need to move heavyweight and dangerous gas cylinders by staff working at the laboratory.

What is gas chromatography?

Gas chromatography (GC) is the technique used for the separation of components of the volatile samples. There are phases involved in gas chromatography. In mobile phase, the sample moves over the stationary phase.

Various constituents of the sample move with different speeds over stationary object causing them to separate.

The core principle of separation is the differential partitioning of sample constituents between the mobile and stationary phases. In gas chromatography, gas is the mobile phase, whereas column coating in the inner surface act as the stationary phase. The vapourised sample is separated on the basis of how long the components of the sample take to come out from the other end of the column and pass into the detector. This time is called the retention time.

GC Zero Air generators advantages The GC Zero air generators for gas chromatography are easy to install. The requirements for its set up is a standard compressed air line and an electrical outlet. Its operating procedures are simple and do not require any labor-intensive monitoring.

Gas Chromatography – Flame Ionization Detector or GC-FID is a commonly used analytical technique in various fields such as the petrochemical, pharmaceutical and in the field of natural gas.

These detectors basically use a Hydrogen/Air flame through which the sample passes and get its organic molecules oxidized to produce electrically charged particles (ions). These ions collectively produce an electrical signal which is measured later.

In all GC techniques, a carrier gas or Mobile phase is required to have low Water and Oxygen impurities since these impurities can interact with the stationary phase which will result in analytical problems like high baseline noise and column bleed. This decreases column lifetime and sensitivity.

These detectors are extremely sensitive towards impurities (hydrocarbon) present in the hydrogen and air supplied for the flame. These impurities cause increased baseline noise which results in the decrease of the detector sensitivity.

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