Nano-Al2O3-based micro solid-phase filter membrane extraction for simultaneous determination of tartrazine and sunset yellow in food

A new micro-solid-phase extraction method based on a prestructured filter membrane was developed to facilitate simultaneous analysis of tartrazine (TA) and sunset yellow (SY) with high performance liquid chromatography (HPLC). A filter membrane impregnated with nano-Al2O3 particles was proposed as a new micro-solid-phase extraction (μ-SPE) device for the preconcentration of colorants in food. The method integrated isolation and concentration in one step, and the adsorbed colorants could be easily eluted from the filter membrane for HPLC analysis. This process does not involve any additional sample treatment. The method is facile and easy to operate. The method showed good linearity, with correlation coefficients >0.9982 in the range of 1.0–200.0 ng mL−1, and low limits of detection (0.10–0.20 ng mL−1). Finally, the recovery values were 86.9–124.0% for the colorants in various food samples. The results indicated that the developed method would be a novel method for rapid determination of TA and SY at trace levels in real samples.