Combined microextraction by packed sorbent and high-performance liquid chromatography-ultraviolet detection for rapid analysis of ractopamine in porcine muscle and urine samples

A method for rapid analysis of ractopamine in porcine muscle and urine was developed and validated. The method was based on combined of microextraction by packed sorbent (MEPS) and high-performance liquid chromatography with ultraviolet detection (HPLC-UV). Parameters of the MEPS procedure affecting extraction efficiency were optimised. Optimum extraction conditions were 100 mu L of sample in five extraction cycles and sampling time of <3 min. Compared with solid-phase extraction, the MEPS procedure required less extraction time, sample volume and consumption of organic solvents. The method demonstrated high linearity within 0.01-2 mu g/mL for porcine muscle and urine samples (R-2 > 0.9985). Accuracies of muscle and urine analyses were 93.9-109.2% and 93.4-105.1%, respectively. Intra-day and inter-day precisions (RSD%) were lower than 11.8% for both analyses. The method was applied for rapid analysis of ractopamine in biological samples. The method was simpler and could be used to screen other beta(2)-agonists in other extraction media. (C) 2013 Elsevier Ltd. All rights reserved.