Triphenylmethanol (also known as triphenylmethanol and TrOH) is an organic compound. It is a white crystalline solid, insoluble in water and petroleum ethers, but soluble in ethanol, ether and benzene. In strongly acidic solutions, it produces a strong yellow color due to the formation of stable "triphenylmethyl" carbon cations. Many derivatives of triphenylmethanol are important dyes.

Therefore, in this study, we examined the characteristics of triphenylmethanol pre-peaks and developed a novel HPLC-ECD based on triphenylmethanol voltammetric oxidation for the determination of theophylline in plasma. The concentration time curve of theophylline in rat plasma was obtained by a novel high performance liquid chromatography-electron capture method to determine the pharmacokinetic parameters.

All chemicals and solvents are reagent grade. Triphenylmethanol (>97.0%) was purchased from Calbiochem (La Jolla, CA, USA). Acetonitrile (>99.8%, HPLC grade), LiClO4 (>98.5%), trichlorothane (>99%), isopropyl alcohol (>99.5%), theophylline (>99%), caffeine (>98.5%) and theobromine (>98%) from Wako Pure Chemical Industries Co. (Osaka, Japan). Uric acid (>98%) and 3-methylxanthine (>98%) were purchased from Tokyo Kasei Kogyo Co., LTD. (Tokyo, Japan). The water used is distilled and used

Theophylline measured the characteristics of the pre-peak

Linear sweep voltammetry of triphenylmethanol with and without theophylline was performed in acetonitrile solutions containing 0.54 mmol L−1 triphenylmethanol and 13mmol L−1 LiClO4 using PFC electrodes. The oxidation peak of +0.85V for Ag/AlgCl was observed on the voltammetry of Ag/AgCl scans from +0.05V to +1.0V (Figure 2, curve a). In the presence of theophylline, a new peak (oxidation pre-peak) appears at a positive potential lower than the oxidation peak (Figure 2, curve B-D).

Based on the triphenylmethanol pre-peak caused by the presence of theophylline on the voltamogram, a new electrochemical detection method was developed for the determination of theophylline by HPLC. The current HPLC-ECD method is highly selective for theophylline detection and can be determined within 10 minutes. The detection limit of theophylline was 0.55μmol L−1 with a linear range of 2.0 to 100μmol L1 (r > 0.999).