Quantification of the β_2-Adrenergic Feed Additives Ractopamine and Salbutamol by Reductive Amination-Assisted Modification

摘要

beta(2)-Adrenergic compounds such as ractopamine and salbutamol can cause smooth muscle relaxation and are used for asthma and chronic obstructive pulmonary disease treatment. However, beta(2)-adrenergic compounds may also cause some adverse cardiovascular effects or behavioral changes in humans; therefore, it is important for analytical chemists to determine the amounts of beta(2)-adrenergic compounds in raw biological materials. Herein, novel analogs for standards and internal standard analogs were synthesized through reductive amination with isotopic H-2-formaldehyde, D-2-formaldehyde, and sodium cyanoborohydride. These analogs were used for quantifying beta(2)-adrenergic compounds such as ractopamine and salbutamol in ground pork samples under multiple reaction monitoring scanning modes by tandem mass spectrometry. H-2-Formaldehyde-modified ractopamine and H-2-formaldehyde-modified salbutamol acting as standards were used to prepare calibration curves, whereas D-2-formaldehyde was used to generate D-2-modified ractopamine and D-2-modified salbutamol analogs acting as internal standards. The H-2-modified ractopamine and H-2-modified salbutamol showed excellent correlation coefficients, limits of detection, and limits of quantification. In mass spectrometric detection, H-2-modified ractopamine showed 202% signal enhancement after modification and H-2-modified salbutamol showed 17% signal enhancement after modification.