Table 2 Control points for the different antimicrobials in blank fish samples
Antimicrobial family | Spiked samples | Blank samples | ||||||
|---|---|---|---|---|---|---|---|---|
Level of analyte spiking (µg/kg) | Mean cpm of spiked samples | Allowance for matrix effect | Control point cpm | Mean blank cpm | Range of blank cpm readings | No. of false positives/no. of samples | False positive rate (%) | |
β-lactams | 25 µg/kg penicillin G | 1275 | Spiked cpm + 20% | 1530 | 2502 | 2160–2907 | 0/30 | 0 |
Sulfonamides | 50 µg/kg sulfamethazine | 1096 | Spiked cpm + 30% | 1424 | 3162 | 1431–6995 | 0/30 | 0 |
Tetracyclines | 0 µg/kg tetracycline | 2524 | Blank cpm − 40% | 1514 | 2524 | 2451–3269 | 0/30 | 0 |
Macrolides | 100 µg/kg erythromycin A | 1765 | Spiked cpm + 20% | 2118 | 2587 | 1906–2952 | 1/28 | 3.6 |
Streptomycin | 25 µg/kg streptomycin | 2574 | Spiked cpm + 30% | 3346 | 4605 | 2942–5488 | 1/20 | 5.0 |
Number of samples used per parameter Ns ≥ 20 | ||||||||