Table 2. Analysis of Artificially Added Imidocarb Milk and Beef Samples by ic-ELISA, LC–MS/MS, and the Immunochromatographic Assay (n = 4)^a,b,c.

		IC-Elisa			LC–MS/MS
samples	spiked	detection level (ng/mL) mean ± SD	recovery rate (%)	CV (%)	detection level (ng/mL) mean ± SD	recovery rate (%)	CV (%)	ICA strip
milk samples	0	ND	NC	NC	ND	NC	NC	–
	2	1.72 ± 0.04	86.0 ± 2.0%	6.94	1.86 ± 0.03	93.0 ± 1.5%	4.56	±
	5	4.63 ± 0.09	92.6 ± 1.8%	4.28	4.75 ± 0.07	95 ± 1.4%	3.07	±
	20	18.70 ± 0.29	93.5 ± 1.5%	2.37	19.12 ± 0.25	95.6 ± 1.3%	1.97	+
beef samples	0	ND	NC	NC	ND	NC	NC	–
	5	4.23 ± 0.16	84.5 ± 3.2%	7.13	4.43 ± 0.15	88.5 ± 3.0%	5.37	±
	10	9.16 ± 0.17	91.6 ± 1.7%	5.17	9.34 ± 0.14	93.4 ± 1.4%	3.25	±
	50	50.61 ± 0.63	101.2 ± 1.3%	3.02	50.45 ± 0.59	100.9 ± 1.2%	2.07	+

^aND, not detectable.

^bNC, not calculated.

^c–, negative: the concentration of imidocarb was below 5 μg/kg; ±, weakly positive: the concentration of imidocarb was in the range of 5–20 μg/kg; +, positive: the concentration of imidocarb exceed 20 μg/kg.