Determination of hydroxyl radical produced by glow discharge plasma with salicylic acid trapping

The effect of discharging voltage and electric conductivity on the concentration of hydroxyl radical produced by glow discharge plasma is investigated in pH=3.2.The salicylic acid is used as the seizure reagent of hydroxyl radical and the high performance liquid chromatography is used to detect 2,5-dihydroxybenzoic acid(2,5-dHBA) and 2,3-dihydroxybenzoic acid(2,3-dHBA) which are produced by the reaction between salicylic acid and hydroxyl radical.It is proved indirectly that there are hydroxyl radicals in glow discharge plasma.The yield of hydroxyl radical produced by glow discharge plasma is reckoned semi-quantitatively in different experiment conditions.The result shows that the concentration of hydroxyl radical is 6.3179×10-5 mol/L when the discharging time lasts 60 min.