▎ 摘　　要

NOVELTY - Preparation of graphene oxide (GO)-titanium oxide-deep eutectic solvent (DES) adsorption material involves mixing sulfuric acid, graphite powder and sodium nitrate at low temperature, adding potassium permanganate, heating, adding hydrogen peroxide to terminate the reaction, washing using hydrochloric acid and water to neutral after the obtained reaction solution was static and the supernatant was discarded, vacuum drying to obtain graphene oxide, ultrasonically dispersing the graphene oxide in ethanol, adding the obtained suspension to tetrabutyl titanate, mixing, adding water and hydrochloric acid, washing, vacuum drying to obtain graphene oxide-titanium oxide powder, heating choline chloride and urea at high temperature to form colorless liquid, cooling to obtain DES, dissolving the DES in methanol, adding the powder, ultrasonically treating, leaving still for overnight, washing, and vacuum drying. USE - Preparation of graphene oxide-titanium oxide-deep eutectic solvent adsorption material used for detecting content of lead and cobalt in Chinese medicinal plant (all claimed) e.g. Paris polyphylla. ADVANTAGE - The graphene oxide-titanium oxide-deep eutectic solvent adsorption material improves the extraction effect of graphene oxide-titanium oxide (GOTiO2), which can be recycled many times after being washed and dried. The detection method has low detection limit and quantification limit, excellent intraday and inter-day precision and is stable. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for detection of lead and cobalt content in plant by combining dispersive micro solid phase extraction (DMSPE) and inductively coupled plasma optical emission spectrometry (ICP-OES), which involves digesting plant sample to be detected after acid treatment, determining volume to obtain the plant sample solution to be detected, adding the graphene oxide-titanium oxide-DES adsorption material to the plant sample solution, oscillating and extracting, centrifuging, obtaining the remaining adsorption material and supernatant, using nitric acid to elute the remaining adsorption material, collecting the eluent, measuring the content of lead and cobalt in the supernatant and the eluent by using the ICP-OES.