Asked by: Boris Prommersberger
science chemistry

What is split ratio in GC?

Last Updated: 19th July, 2021

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The split ratio is calculated by dividing the column carrier gas flow rate into the split vent flow rate. For example, a 1:5 split ratio means that 5 times the amount of carrier gas is flowing out of the split vent in comparison with the column.

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Thereof, what is split injection in gas chromatography?

Split injection with capillary gas chromatography (GC) has typically been used when analyzing neat or concentrated samples. Split injection involves introducing only a small portion of the sample to the GC column, mainly to avoid overloaded peaks that corrupt the separation efficiency of the column.

Also, how do you find the split ratio? For example: If the desorb flow is 50 mL/min and the inlet split flow is 100 mL/min, then the inlet split ratio is 150:50 (i.e. 3:1) – meaning that 1/3 of the sample will go to the cold trap.

Thereof, what is split and splitless in GC?

If a split injection is used then there won't be enough analyte injected on-column to detect. This is called the splitless mode and it's used for trace because all the analyte mass in a 1 µL injection goes on column, and is not split; and so this is the most sensitive the method can be: a splitless injection.

What causes peak splitting in GC?

Many times, peak splitting can happen because of a faulty injection. You need to check the injection liner and the glass wool inside. If the proper liner is not used or the glass wool is not properly inserted inside the liner, it may split the peak.

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