Determination of Squalene in Organic Extra Virgin Olive Oils (EVOOs) by UPLC/PDA Using a Single-Step SPE Sample Preparation

In this paper, a simple extraction and fast detection procedure was used to determine squalene (SQ) in extra virgin olive oils (EVOOs). SQ was purified from EVOOs by an efficient single-step solid phase extraction (SPE), and its content was determined using an UPLC-PDA instrument. The adopted technique was evaluated for accuracy, linearity, sensitivity, and repeatability. The precision of the SPE extraction was satisfactory and the mean recoveries were 91.9 ± 0.4 and 96.3 ± 0.3 % for 25 and 50 mg L−1 level of addition, respectively. The selected chromatographic conditions allowed a very fast SQ determination; in fact, it was well separated in ∼0.54 min with good resolution. The UPLC method showed a good linearity in the range 50–500 mg L−1 (R2 = 0.9998). Method sensitivity was evaluated by measuring the limits of detection (LOD) that was 0.3 mg L−1. The method was utilized for SQ determination in 33 different organic EVOO samples, coming from different countries (Turkey, Tunisia, Spain, Portugal, Greece, USA, Slovenia, Albania, Israel, Italy) and the data were statistically evaluated.