FLOW-INJECTION ANALYSIS DETERMINATION OF PHENOLS IN KEROSENE AND NAPHTHA BY MEMBRANE EXTRACTION PRECONCENTRATION

The determination of phenolic compounds in kerosene by flow-injection analysis has been investigated. The approach is based on the reaction of phenols with 4-aminoantipyrine in the presence of an oxidizing agent to form red compounds easily detectable at 500 nm. Phenolics are separated from kerosene through a silicone membrane into a basic acceptor stream which contains the 4-aminoantipyrine reagent followed by confluence with the oxidizing reagent. The sensitivity of the system can be easily manipulated by modifying the size of the extraction cell and the preconcentration time. Direct UV detection at 240 nm was also tested, the acceptor stream being a basic buffered solution.