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Confirmatory analysis of β ‐lactam antibiotics in kidney tissue by liquid chromatography/electrospray ionization selective reaction monitoring ion trap tandem mass spectrometry
Author(s) -
Fagerquist Clifton K.,
Lightfield Alan R.
Publication year - 2003
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/rcm.964
Subject(s) - chemistry , chromatography , cloxacillin , dicloxacillin , tandem mass spectrometry , selected reaction monitoring , electrospray ionization , ceftiofur , detection limit , mass spectrometry , liquid chromatography–mass spectrometry , high performance liquid chromatography , ampicillin , antibiotics , biochemistry
Eleven β ‐lactam antibiotics were analyzed in fortified and incurred beef kidney tissue using high‐performance liquid chromatography/electrospray ionization/selective reaction monitoring‐ion trap tandem mass spectrometry (LC/ESI‐SRM‐MS n ). The analytes included: deacetylcephapirin, amoxicillin, cephapirin, desfuroylceftiofur cysteine disulfide (DCCD, a biomarker of ceftiofur), ampicillin, cefazolin, Pen G, oxacillin, cloxacillin, naficillin and dicloxicillin. Analytes were extracted with acetonitrile and water. Clean‐up was performed by solid‐phase extraction. Limits of confirmation in fortified tissue are as follows (tolerances or target levels in parentheses): deacetylcephapirin: 10–50 ng/g (100 ng/g); amoxacillin: 50–100 ng/g (10 ng/g); cephapirin: 10 ng/g (100 ng/g); DCCD: 500 ng/g (8000 ng/g); ampicillin: 10 ng/g (10 ng/g); cefazolin: 10 ng/g (10–50 ng/g); Pen G: 10 ng/g (50 ng/g); oxacillin: 10 ng/g (10–50 ng/g); cloxacillin: 10 ng/g (10 ng/g); naficillin: 10 ng/g (10–50 ng/g); dicloxacillin: 100–500 ng/g (10–50 ng/g). The present method was also tested on incurred kidney tissue that had previously been analyzed using a microbial assay. Good correspondence was found between the results from this new method and the bioassay. However, the present method is much more specific and, in several cases, more sensitive than the bioassay. In addition, the time of analysis is significantly shorter than the bioassay. We also found that SRM MS n was superior in the analysis of unknown incurred tissue than full spectrum MS n . We also obtained an MS/MS spectrum of DCCD that is significantly at variance with previously published fragmentation spectra. Published in 2003 by John Wiley & Sons, Ltd.