Table 2 Spiked recoveries and coefficient of variations (CVs) of one-step ci-ELISA and LFIA for colistin in animal feed and food (n = 4)
Method | Sample type | Spiked concentration | Measured concentration | Recovery, % | CV, % |
|---|---|---|---|---|---|
One-step ELISA | Swine feed, mg/kg | 0 | < LOD | – | – |
1.0 | 0.93 ± 0.11 | 93.20 | 11.40 | ||
2.0 | 1.86 ± 0.18 | 93.03 | 9.53 | ||
4.0 | 3.27 ± 0.08 | 81.63 | 2.48 | ||
Chicken feed, mg/kg | 0 | < LOD | – | – | |
1.0 | 1.08 ± 0.09 | 108.00 | 8.33 | ||
2.0 | 1.93 ± 0.14 | 96.57 | 7.30 | ||
4.0 | 3.89 ± 0.18 | 97.34 | 4.56 | ||
Milk, μg/kg | 0 | < LOD | – | – | |
25 | 27.53 ± 2.97 | 110.13 | 10.78 | ||
50 | 49.87 ± 3.41 | 99.74 | 6.83 | ||
100 | 87.44 ± 7.79 | 87.44 | 8.91 | ||
Meat, μg/kg | 0 | < LOD | – | – | |
75 | 73.14 ± 8.89 | 97.52 | 12.16 | ||
150 | 116.75 ± 13.13 | 77.83 | 11.25 | ||
300 | 253.17 ± 24.79 | 84.39 | 9.79 | ||
LFIA | Swine feed, mg/kg | 0 | < LOD | – | – |
0.5 | 0.44 ± 0.07 | 87.86 | 16.75 | ||
1.0 | 1.14 ± 0.16 | 114.45 | 13.94 | ||
2.0 | 1.74 ± 0.15 | 87.23 | 8.57 | ||
Chicken feed, mg/kg | 0 | < LOD | – | – | |
0.5 | 0.56 ± 0.05 | 112.84 | 9.04 | ||
1.0 | 0.95 ± 0.13 | 95.43 | 13.57 | ||
2.0 | 1.92 ± 0.12 | 95.85 | 6.03 | ||
Milk, μg/kg | 0 | < LOD | – | – | |
25 | 28.35 ± 3.79 | 113.38 | 13.37 | ||
50 | 40.59 ± 5.26 | 81.17 | 12.96 | ||
100 | 89.93 ± 8.96 | 89.93 | 9.96 | ||
Meat, μg/kg | 0 | < LOD | – | – | |
75 | 74.45 ± 13.37 | 99.27 | 17.96 | ||
150 | 150.72 ± 20.36 | 100.48 | 13.51 | ||
300 | 234.66 ± 34.52 | 78.22 | 14.71 |