Determination of Seven Preservatives in Tobacco Flavor by RP-HPLC

A method for simultaneously determining 7 preservatives in tobacco flavors by reversed-phase high performance liquid chromatography(RP-HPLC) with a variable wavelength detector(VWD) was developed.The parameters such as extraction solvent,extraction time,mobile phase,VWD wavelength were tested and optimized.The preservatives in 9 tobacco flavor samples were quantitatively determined respectively,the results showed that:① ultrasonic extraction with methanol for 5 min was more effective;② the 7 preservatives were completely separated in 40 min by reversed-phase HPLC with a Dikma Platisil ODS column under a gradient elution with methanol and water(adjusted pH) as mobile phase at a flow-rate of 1.0 mL/min;③ at a wavelength of 230 nm in the first 10 min to detect benzoic acid,salicylic acid,sorbic acid,then at 254 nm to detect esters of methyl parabenzoic acid presented higher sensitivity;④ the recoveries of preservatives were from 97.0% to 99.6% with the relative standard deviation(RSD) of 5 repeat tests under 5%(1.3%-3.1%);⑤ none of the preservatives was found in Sample No.8,the preservatives detectable in the other samples mainly were benzoic acid and sorbic acid,esters of methyl parabenzoic acid were found in 3 samples and salicylic acid was not detected in all samples.This method is suitable for determining the 7 preservatives in tobacco flavors.