Use of porous graphitic carbon coupled with mass detection for the analysis of polar phenolic compounds by liquid chromatography

Phenolic compounds present in olive mill wastewater (OMW) need to be quanti fied because of their pollution capacity toward the environment. In the pre sent study, six representative phenolic compounds of OMW were chosen to dev elop a LC-MS method. The high polarity of the compounds caused problems whe n using traditional reversed-phase liquid chromatography (RPLC). Consequent ly, a method was developed on another kind of chromatographic phase: Porous Graphitic Carbon (PGC) involving the use of a tetrahydrofuran (THF) gradie nt. The influence of THF as mobile phase in LC-MS coupling, which is not co mmon practice, was evaluated. In Atmosperic Pressure Chemical Ionisation (A -PCI) in the negative ion mode, the presence of THF in the mobile phase did not degrade the MS signal of the target compounds in the conditions studie d. On the contrary, an improvement was even observed when the percentage of THF increased. The proposed PGC-LC-MS method was selective and linear for the six phenolic compounds analysed with limits of quantification lower tha n 5 ppm in all cases. The precision was satisfactory (pooled RSD around 6%) . The analyses of OMW matrix spiked sample confirmed the good performance o f the proposed method (C) 2001 Elsevier Science B.V. All rights reserved.