Ammonium hydroxide ar grade

Ethanol, tetramethylammonium hydroxide (TMAH), and tetraethyl orthosilicate (TEOS) were acquired from Beijing Chemical Corporation. Ammonium hydroxide (AR grade) and 1,10-phenanthroline (phen) were obtained from Sinopharm Chemical Reagent Co., Ltd. (Shanghai, China). Europium oxide was sourced from Darui Company (Shanghai, China). Trifluoroacetylacetone (TTA) was procured from Shanghai McLean Biochemical Co., Ltd. Solvent-grade ethanol was utilized directly without further treatment. Ethyl orthosilicate underwent distillation prior to use. High-purity water (Pall Purelab Plus) with a resistivity of 18 M Ω/cm was employed in all experimental procedures.

Apixaban, betrixaban, rivaroxaban, edoxaban, and ²H₄-rivaroxaban were purchased from MedChemExpress (Monmouth Junction, NJ, USA). ²H₃-Apixaban, ²H₆-edoxaban, and ²H₆-betrixaban were obtained from SHANGHAI ZZBIO CO., LTD (Shanghai, China). HPLC-grade methanol and acetonitrile were purchased from Fisher, USA. Ammonium acetate (A.R. grade), ammonium formate (A.R. grade), and ammonium hydroxide (A.R. grade) were bought from Sinopharm Chemical Reagent Co., Ltd. (Beijing, China). Sigma-Aldrich Corp. (St. Louis, MO, USA) supplied the formic acid (A.R. grade) and dimethyl sulfoxide (HPLC-grade). Deionized water was purified with a Milli-Q^® Ultrapure water system (Millipore Corporation, Bedford, MA, USA).