Ultrasound probe enhanced enzymatic hydrolysis for rapid separation of β2-adrenergic agonists from animal urine and livestock wastewater: Applicability to biomonitoring investigation

Abstract

BackgroundAn increasing number of β2-adrenergic agonists are illicitly used for growth promoting and lean meat increasing in animal husbandry in recent years, but the development of analytical methods has lagged behind these emerging drugs. ResultsHere, we designed and developed an ultrasound probe enhanced enzymatic hydrolysis reactor for quick separation and simultaneously quantification of 22 β2-adrenergic agonists in animal urine and livestock wastewater. Owing to the enhancement of the conventional enzymatic digestion through the ultrasound acoustic probe power, only 2 min was required for the comprehensively separation of β2-adrenergic agonists from the sample matrices, making it a much more desirable alternative tool for high-throughput investigation. The swine, bovine and sheep urines (n = 287), and livestock wastewater (n = 15) samples, collected from both the north and south China, were examined to demonstrate the feasibility and capability of the proposed approach. Six kinds of β2-adrenergic agonists (clenbuterol, salbutamol, ractopamine, terbutaline, clorprenaline and cimaterol) were found in animal urines, with concentrations ranged between 0.056 μg/L (terbutaline) and 5.79 μg/L (clenbuterol). Up to nine β2-adrenergic agonists were detected in wastewater samples, of which four were found in swine farms and nine in cattle/sheep farms, with concentration levels from 0.069 μg/L (tulobuterol) to 2470 μg/L (clenbuterol). SignificanceInterestingly, since β2-adrenergic agonists are usually considered to be abused mainly in the pig farms, our data indicate that both the detection frequencies and concentrations of these agonists in the ruminant farms were higher than the pig farms. Furthermore, the findings of this work indicated that there is a widespread occurrence of β2-adrenergic agonists in livestock farms, especially for clenbuterol and salbutamol, which may pose both food safety and potential ecological risks. We recommend that stricter controls should be adopted to prevent the illegally usage of these β2-adrenergic agonists in agricultural animals, especially ruminants, and they should also be removed before discharging to the environment.