Influence of Water in Samples on Residues Analysis of Beta-Agonists in Porcine Tissues and Urine Using Liquid Chromatography Tandem Mass Spectrometry

The influence of water in samples on matrix effects and recoveries of analytes were investigated during the determination of residues of nine beta-agonists including salbutamol, terbutaline, cimaterol, fenoterol, clorprenaline, ractopamine, tulobuterol, clenbuterol, and penbuterol in porcine liver, muscle, and urine samples with liquid chromatography tandem mass spectrometry. Lyophilization procedure was adopted for sample moisture removal. The results showed that there were weak suppression effects for all target analytes except ractopamine, and no significant differences were found between fresh and lyophilized samples with respect to matrix effects of nine beta-agonists (P > 0.05). However, most analytes’ recoveries in the range of 85.0–115 % were obtained in lyophilized samples, while only a few ones were found in fresh samples. There are significant differences in recoveries for most analytes between fresh and lyophilized samples (P < 0.05). In conclusion, water in sample matrices does not affect matrix effects significantly while it might be one of the reasons causing poor recovery. Water removal is effective to improve recoveries of analytes without increasing matrix effects.