Multicommuted Flow Injection Analysis Using Chemiluminescence Detection (MCFIA-CL) for Olive Oil Analysis

Abstract

This article describes the applicability of multicommuted chemiluminescence flow injection analysis (MCFIA-CL) to the determination of olive oil quality parameters. Two automated MCFIA methods were developed and validated for the determination of peroxide value (PV) and phenolic compounds in commercial extra virgin olive oil samples. The PV method proposed is based on the chemiluminescent (CL) signal produced from luminol oxidation by the olive oil hydroperoxides in basic conditions using Co(II) as catalyst, while the determination of phenolic compounds is based on CL emission generated from permanganate reduction in acidic media by hydroalcoholic extracts of olive oil. The flow assemblies for automated liquid handling consisted, respectively, of 2 and 3 three-way solenoid valves, which were controlled by a homemade electronic interface and Java-written software together with a CL detector. The signals obtained correlated well against the PV and total phenolic contents measured by the official and the Folin-Ciocalteu methods, respectively. The linear response range observed for PV allows checking whether the samples are in compliance with European Union regulations. On the other hand, the phenolic compounds content also correlated well with data reported by the well-known FC method across the entire typical concentration range of these compounds in virgin olive oils. The proposed methods are faster, safer, and more environmentally friendly than the respective official or classical ones involving lower consumption of solvents, reagents, and sample, as well as less waste generation together with a high sample throughput. Moreover, they are straightforward and cost-effective to implement in routine analysis, and can be regarded as a feasible alternative to the official or classic methods.