Boric acid when burnt with ethyl alcohol gives a green edged flame due to the combustion of

When ortho boric acid is burnt with ethyl alcohol in presence of Conc H2SO4 gives triethyl ortho borate.When the vapours of triethyl borate ignited burn with a green edged flame.The green edged flame is due to the combustion of ethyl borate.This test is used to detect the borates and boric acid in qualitative analysis.