Comparative residue depletion and tissue distribution of three β-adrenergic agonists in broiler chickens.

β-Adrenergic agonists are banned as growth promoters in the European Union, and clenbuterol and salbutamol are routinely screened in poultry under national residue-control programs; characterizing their residue behavior in edible tissues therefore supports the detection of illicit use. This study examined the residue depletion and tissue distribution of salbutamol, clenbuterol, and terbutaline in 168 Ross 308 broiler chickens. Each compound was administered in drinking water at 2.5 or 5 mg/L for seven consecutive days, chosen to model a covert exposure route rather than an authorized feed protocol, followed by a withdrawal period. Concentrations in breast muscle, liver, and kidney were quantified using a validated LC-MS/MS method compliant with Commission Implementing Regulation (EU) 2021/808. Residue values are group mean concentrations of three birds per group per sampling point (n = 3); because the individual per-bird results were not retained, no measures of dispersion are reported for the residue data. Quantifiable residues were detected in all three tissues at the first post-treatment sampling point, with the highest concentrations in kidney and liver and the lowest in breast muscle. Residues declined over the withdrawal period; terbutaline depleted most rapidly and clenbuterol persisted longest, and apparent depletion half-lives derived by log-linear regression were 1.1-1.5 days in liver and 0.7-1.2 days in kidney. By Day 46, all residues were below their respective matrix-specific decision limits (CCα), and no growth-promoting effect was observed for any compound at either concentration. Under this short drinking-water exposure, the three β-agonists showed distinct, tissue-dependent residue-depletion profiles but no measurable growth-promoting response in broilers. The comparative dataset, referenced to validated CCα values, supports residue surveillance and food-safety risk assessment of β-agonist residues in poultry.