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Advantages of headspace over liquid injections

 Which one is your favorite technique in case of GC? Is it liquid injection or headspace? Mine is the headspace, as headspace can outperform liquid injection in many ways.

#1 For residual solvent analysis, the liquid injection can’t be used in case if sample does not dissolve completely. However, the headspace can be used even though the sample does not dissolve completely in given diluent.

#2 The liquid injection will introduce all the components present in a sample solution on to column and may end up damaging column if few of the injected compounds do not vaporize.  However, headspace allows injection of vaporized components of sample solution and will not introduce non-vaporized components on to column and eventually protect column from contamination and harmful components.

#3 The liquid injection technique gets affected by viscosity of the sample solution. Whereas, headspace will never get impacted due to viscosity of sample solution.

#4 The liquid injection may lead to imprecise result due to air bubble in syringe. Whereas, air bubble is never be an issue in case of headspace.

#5 With liquid injection, sample beyond capacity of syringe volume can't be injected. However, with headspace, sample with higher volume or higher time can be injected.

#6 The recovery or extraction of analyte is depends on diluent strength in case of liquid injection. Whereas, in case of headspace, the recovery of analyte gets improvised due to combination of diluent strength, temperature and pressure.

#7 The gaseous samples can’t be analyzed using liquid injection. Whereas, gaseous samples can be very well analyzed using headspace.

I have tried to summarize few advantages of headspace over liquid injection. Please add, if I have missed any. And do let me know which one is your favorite technique?

Liquid injection or headspace?

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