Preparation of mesoporous silica SBA-15 modified by CTAB for extraction, preconcentration and determination of trace amounts of carmoisine in food samples

Abstract A simple, sensitive, and high-efficiency method was presented for the extraction and preconcentration of trace amounts of carmoisine. In this method, SBA-15 modified with cetyl trimethyl ammonium bromide (SBA-15/CTAB) was used as a suitable absorbent. UV-Vis technique (ʎmax=522 nm) was used to study the amount of carmoisine absorption. The characteristics of SBA-15 and SBA-15/CTAB were investigated by transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET), thermogravimetric analysis (TGA), Fourier transform infrared (FT-IR), map analysis, Energy dispersive X-ray (EDX), and CHN elemental analysis. Effective parameters (pH, amount of nanocomposite, type of recovery solvent, surfactant volume, etc.) for the extraction of carmoisine by SBA-15/CTAB were investigated. The merit figures of the method, such as accuracy, detection limit, preconcentration factor, and enrichment factor have been obtained with suitable results. The calibration curve was obtained linearly in the range of 0.3–20 ng mL− 1 with a detection limit of 0.12 ng mL− 1. A concentration factor was calculated at about 50. The proposed method for measuring carmoisine was applied at a negligible level in food samples such as cherry juice, blackberry juice, pomegranate juice, red grape juice, blueberry juice, cherry jelly, ketchup, tomato paste, smarties, and cherry compote with satisfactory results.