Distribution and Depletion of Ractopamine in Goat Plasma, Urine and Various Muscle Tissues.

This study investigated the ractopamine (RAC) distribution and depletion process in goat plasma, urine and various muscle tissues which were associated with a potential risk for consumer health. The experiment was carried out in 21 goats (18 treated and 3 controls). Treated animals were administered orally a dose of 1 mg/kg body mass per day for 28 consecutive days and randomly sacrificed on Days 0.25, 1, 3, 7, 14 and 21 of the withdrawal period. RAC in goat samples was analyzed by using ultra-high performance liquid chromatography-quadrupole-orbitrap high-resolution mass spectrometry. RAC was below the limits of detection (LOD = 0.15 ng/mL) in plasma while which was higher than the LOD in urine on withdrawal day 21. The residues in goat longissimus dorsi muscle, biceps femoris muscle and triceps surae muscle were differed significantly. These findings demonstrated that urine can be used as the target matrix for monitoring RAC abuse in goat.