With the popularity of herbal tea in China, many food fraudsters have added illegal drugs to herbal tea to enhance its functions, among which aminopyrine is widely abused as an antipyretic and analgesic. Presently, there is no immunoassays for aminopyrine, and it is difficult to achieve real-time detection in the field. Based on a polyclonal antibody of aminopyrine with high specificity and sensitivity, an optimal combination of coating antigen/antibody was obtained by screening different coating antigens. On this basis, a sensitive ic-ELISA method was established to detect aminopyrine in herbal tea. The detection limit of the ic-ELISA was 0.18 ng mL−1, which was much lower than the 100 ng mL−1 required as a standard. The method had good consistency with LC-MS in the detection of actual samples and could be used as a reliable method for the detection of aminopyrine in herbal tea.
Leiwenxuan Yang,Gaohua Hu,Yali Huang,Chen Wang,Xin Liu,Chengyin Lu,Hongping Chen,Jianyang Zhang,Guicen Ma
Sulfites are used widely in food and beverage production to prevent browning or oxidation. However, the overingestion of sulfites is harmful to human health and may cause medical complications. Chinese herbal teas have been widely consumed for centuries. However, sulfite levels in Chinese herbal teas are rarely investigated and reported. Here, we present a simple, sensitive, and quantitative method to determine sulfites in Chinese herbal teas using ultrahigh-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) coupled with dispersive solid phase extraction. The method utilized a SeQuant ZIC-HILIC column for separation, and the optimal gradient eluents consisted of acetonitrile and aqueous solution with 0.1% acetic acid and 10 mM ammonium acetate. Porous chitosan/partially reduced graphene oxide/diatomite (CS/prGO/DM) composites were used as efficient dispersive solid phase extraction adsorbents for sample preparation. Several parameters were investigated during the extraction process, including sample-to-extraction solvent volume ratios, the extraction procedure and dosage of the adsorbent. Under the optimum conditions, the developed method gave a good determination coefficient (r2 > 0.99), low detection limits (0.51–12.1 μg kg−1) and high recoveries in the range of 83.8–102.7% at different spiked levels. The method has the great advantages of being time saving, good reproducibility and much lower detection limits when compared to titration methods. The method was further applied to analyze real herbal tea samples collected from the local market, demonstrating that our developed method is robust and useful for determining sulfites in practical application.
危险品化学品经营许可证（带存储）