COMPARISON OF NAPHTHENIC ACID DERIVATIZATION EFFECTIVENESS BY DISTINCT REAGENTS

Derivatization is basically denominated as the conversion of polar components into appropriate chemical species to chromatography.The derivatives produced have high volatility and stability improving selectivity and sensitivity of detection.Derivatization of the naphthenic acids is crucial for GC-MS analysis.Naphthenic acids (NAs) are natural component of crude oil and comprise a complex mixture of the carboxylic acids with different structures.Due to heterogeneous composition, gas chromatography coupled to mass spectrometry has been applied to the characterization of NAs mixtures.Three different derivatizing reagents were tested in this paper in order to study their effectiveness for available commercial naphthenic acids.The results indicated that diazomethane was the most efficient reagent in the ester derivative production, although MTBSTFA has been common used to naphthenic acid samples.Therefore, NAs applied in this work, probably present a great complexity of the structures that the specific silylating reagent did not achieve a total conversion.