Versatile and reliable extraction of phytosterols employing sonochemical synthesized molecularly imprinted polymer

Phytosterols (PSs) are bioactive compounds in the sterol family, present in numerous complex food and plant matrices in free and conjugated forms. The interest in these compounds arises for phytotherapeutic purposes, particularly for their action on cholesterol metabolism and impact on cardiovascular diseases. There is a need to develop approaches that can selectively extract target analytes and accurately identify and quantify them with high precision. This work proposed the synthesis of molecularly imprinted polymers (MIPs) for PSs with a sonochemical approach, enabling a rapid polymerization step (5 min). This proposed MIP was able to extract 8 PSs (brassicasterol, stigmastanol, campesterol, campestanol, stigmasterol, β-sitosterol, Δ5-avenasterol, α-spinasterol) from a wide range of plant and food matrices belonging to different classes (Brassicaceae, dried fruits and Leguminosae) and was coupled to ultra-high liquid chromatography with tandem mass spectrometry (UHPLC-MS/MS). MIP based on dispersed solid phase extraction (dSPE-MIP) and targeted analysis has proven to be particularly effective in addressing the challenges associated with the complexity of plant-derived matrices, minimising interferences. This was demonstrated by the excellent control of the matrix effect, which was within ±15 %, ensuring the robustness and reliability of the method. The identification and quantification of 8 different PSs was successfully achieved with satisfactory recovery values ranging from 65 % to 100 %. The proposed strategy offers an affordable alternative to classical methods, providing enhanced sensitivity, selectivity and overall performance.