Determination of β-Agonist Residues in Animal-Derived Food by a Liquid Chromatography-Tandem Mass Spectrometric Method Combined with Molecularly Imprinted Stir Bar Sorptive Extraction

Table 1

Linear dynamic range, correlation coefficients, LODs and LOQs, average recoveries, and interday and intraday precisions achieved for the six β-agonists.

Compounds	Linear range (μg/L)	R^2	LOD^a (μg/L)	LOQ^b (μg/L)	Recovery (%)			Interday assay^c (RSD %, )	Intraday assay^c (RSD %, )
					Spiked level (μg/kg)	Pork	Liver
Clenbuterol	0.5–35	0.9991	0.05	0.10	1.0	85.0	87.2	3.9	4.2
					5.0	86.5	97.9
Salbutamol	1–35	0.9981	0.10	0.25	1.0	85.3	84.5	4.5	5.1
					5.0	76.5	88.2
Ractopamine	1–35	0.9952	0.15	0.35	1.0	75.8	80.2	5.1	5.3
					5.0	83.6	72.6
Mabuterol	1–35	0.9978	0.10	0.25	1.0	81.2	80.8	4.4	2.6
					5.0	85.3	84.9
Brombuterol	1–35	0.9936	0.10	0.25	1.0	84.5	82.6	4.6	3.8
					5.0	85.8	85.6
Terbutaline	1–35	0.9957	0.15	0.30	1.0	84.3	83.1	4.9	4.1
					5.0	85.4	85.2

^aS/N = 3; ^bS/N = 10; ^cassays at 5.0 μg/kg level.