Polyurethane functionalized silica aerogel for in-tube solid-phase microextraction of estrogens prior to high performance liquid chromatography detection

[Display omitted] •A new silica aerogel functionalized with polyurethane was developed.•The aerogel was in situ produced on the surface of basalt fibers for IT-SPME.•The aerogel exhibited satisfactory extraction performance towards estrogens.•Extraction mechanism included π-π, hydrophobic and hydrogen-bonding interactions.•Online IT-SPME-HPLC method was developed to detect five estrogens in real samples. In order to improve the extraction performance and stability of silica aerogel, the polyurethane was used to functionalize silica aerogel. A silica aerogel hybridized with polyurethane was in situ prepared on the surface of basalt fibers for in-tube solid-phase microextraction (IT-SPME). When a polyetheretherketone tube filled with the modified basalt fibers was combined with high performance liquid chromatography (HPLC), an online IT-SPME-HPLC method for the detection of five estrogens in environment samples was developed. This method achieved wide linear ranges (0.1–50.0 μg L−1 and 0.03–100.0 μg L−1), low limits of detection (0.01 μg L−1 and 0.03 μg L−1), high enrichment factors (1178–3102), and acceptable relative standard deviations (n = 5, 2.1–4.9% and 3.7–6.9%) for intra-day and inter-day tests. Compared with other methods, the method exhibited some superiorities including online analysis, better sensitivity and faster test. It has been verified that the method can sensitively determine some estrogens from water samples.