Determination of Phenolic Compounds in Water by Solid Phase Membrane Extraction Coupled with Ultrasonic Assisted Desorption and Derivation

A new pretreatment technology of phenolic compounds analysis in water was established. When the pH value of the water sample was 3-4, the extraction of phenolic compounds in 500 mL water sample could be completed in 5 min by using SDB-XC solid phase extraction membrane. Then the folded membrane was put into a reaction bottle, in which five fluorinated benzyl bromide solution was used as the derivatization reagent to complete the elution and derivatization of phenolic compounds on the membrane by 20 min ultrasound. HP-5MS column （30 m×0.25 mm×0.25 μm） was selected as analytical column, the detection could be completed within 10 min by using negative chemical ionization source. In this method, the selection of membrane, the control of acidity, derivation condition, ultrasonic condition and interference situation were analyzed and optimized. The results showed that the correlation coefficient of each component was greater than 0.997 in the linear range of 10-200 μg/L. The recoveries of different concentrations were 70%-107%, and the relative standard deviations were 3.8%-10.4%. Some phenolic compounds were detected in actual samples by this method. The method can achieve the rapid extraction, synchronous elution, low pollution and high sensitivity detection of samples.