[karan]

How can i determine the concentration of gases such as Hydrogen Sulfide (H2S), Nitrogen Dioxide(NO2), Carbon Dioxide(CO2), Sulfur Dioxide(SO2)?? Can it be done by titration i.e. volumetric analysis or is there any other method to do so?

[Arkcon]

Can it be done by titration i.e. volumetric analysis or is there any other method to do so?

Its not very likely you can do a good job dissolving the gasses completely, then conducting a wet chemical reaction.  A gas chromatograph is usually used for a gaseous sample.

[Enthalpy]

It's often desired to measure, or at least detect, H₂S in ppm or sub-ppm concentration. SO₂ measures must often be sensitive to low concentrations too. This would restrict the possible analysis methods.