Table 5.
Confirmatory results for suspect samples analyzed by LC-MS/MS.
| Sample | AMPI (μg/kg) | AMOXY (μg/kg) | PEN G (μg/kg) | CLOXA (μg/kg) | DICLOXA (μg/kg) |
|---|---|---|---|---|---|
| 2009 | |||||
| DP021 | nd | nd | C (2.2) | nd | nd |
| BF037 | nd | nd | nd | nd | nd |
| DP071 | nd | nd | nd | nd | nd |
| BB110 | nd | nd | NC (98) | nd | nd |
| DE115 | nd | nd | <LoQ | nd | nd |
| BB120 | nd | nd | nd | nd | nd |
| EI121 | nd | nd | NC (1973) | nd | nd |
| DO125 | nd | nd | nd | nd | nd |
| GO128 | nd | nd | nd | nd | nd |
| DE138 | nd | nd | NC (5.5) | nd | nd |
| DP146 | nd | nd | nd | nd | nd |
| DE168 | nd | NC (7.2) | nd | nd | nd |
| DP175 | nd | nd | C (20) | nd | nd |
| DE185 | nd | C (2.1) | C (4.1) | nd | nd |
| DE191 | nd | NC (14) | nd | nd | nd |
| DP195 | nd | NC (7.6) | nd | nd | nd |
| DY196 | nd | nd | nd | nd | nd |
| IK196 | NC (8.9) | nd | nd | C (20) | nd |
| FV200 | nd | nd | nd | nd | nd |
| FV201 | NC (171) | nd | <LoQ | NC (439) | nd |
| PM203 | nd | nd | nd | nd | nd |
| BD206 | nd | nd | <LoQ | nd | nd |
| BL209 | <LoQ | nd | nd | nd | nd |
| DO213 | nd | nd | nd | nd | nd |
| GO214 | nd | nd | nd | nd | nd |
| 2010 | |||||
| KA216 | <LoQ | nd | nd | <LoQ | nd |
| GO236 | nd | nd | NC (24) | nd | nd |
| GO244 | nd | nd | NC (24) | nd | nd |
| KA270 | nd | nd | nd | nd | nd |
| KP291 | nd | nd | NC (6.4) | nd | nd |
| DE292 | nd | nd | nd | <LoQ | nd |
| DK293 | nd | nd | nd | nd | nd |
| IK294 | <LoQ | nd | C (5.1) | <LoQ | nd |
| EI294 | <LoQ | nd | nd | NC (42) | nd |
| DY296 | nd | nd | nd | nd | nd |
| DP297 | nd | NC (15) | nd | nd | nd |
| BD298 | nd | nd | nd | nd | nd |
| DO299 | nd | nd | nd | NC (49) | nd |
| BL317 | nd | nd | nd | nd | nd |
| DE318 | nd | C (4.6) | nd | nd | nd |
| DE319 | nd | nd | nd | nd | nd |
| FR320 | NC (784) | nd | NC (156) | NC (542) | nd |
| KP379 | nd | nd | NC (6.9) | nd | nd |
| GA390 | nd | nd | nd | <LoQ | nd |
| DO391 | nd | nd | nd | nd | nd |
| DP392 | nd | nd | nd | nd | nd |
| PM393 | nd | nd | nd | <LoQ | nd |
| FV394 | nd | nd | nd | nd | nd |
| GO426 | nd | nd | nd | nd | nd |
| DP461 | C (2.5) | nd | nd | C (32.4) | nd |
| DP514 | nd | NC (43) | nd | nd | nd |
| GO554 | nd | nd | nd | nd | nd |
| DE587 | NC (7.0) | nd | C (15) | nd | nd |
| KP661 | nd | nd | C (5.1) | ND | nd |
| DK671 | nd | nd | nd | nd | nd |
AMOXY = amoxicillin; AMPI = ampicillin; C = compliant (sample containing a concentration of β-lactam residues lower or equal to CCα); CLOXA = cloxacillin; DICLOXA = dicloxacillin; LC-MS/MS = liquid chromatography-tandem mass spectrometry; NC = not compliant (sample containing a concentration of β-lactam residues higher than CCα); LoQ = limit of quantification (corresponding to the 1st spiking level used in validation of the LC-MS/MS method: 2 μg/kg for AMP, AMX, PNG; 15 μg/kg for CXA and DCX); nd = not detected; PEN G = penicillin G; RSD = relative standard deviation.