challenges in antibiotics analysis in environmental samples · liquid chromatography/mass...
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Challenges in Antibiotics Analysis in Environmental Samples
Diana S. Aga
What Antibiotics Should We Analyze For?
US Food and Drug Administration, 2015. Summary Report: Antimicrobials Sold or Distributed for Use in Food- Producing Animals.
Class Annual Total (Kg)
Tetracyclines 6,514,779
Ionophores (e.g. monensin) 4,434,657
Penicillins 828,721
Macrolides 563,251
Sulfonamides 384,371
Aminoglycosides 270,342
Lincosamides 236,450
Cephalosporins 28,337
Others (e.g. Polypeptides, Streptogramins) 1,527,646
Importance of Transformation Products: Tetracyclines
Tetracycline Oxytetracycline Chlortetracycline
Transformations
Importance of Metabolites: Sulfonamides
Analytical TechniquesLiquid chromatography/mass spectrometry (ion-trap, triple quad, Q-ToF, Orbitrap) vs.
Biological Assays (ELISA, microbial activity assay)
sulfonamides Tetracyclines Macrolides
ELISA Method (striped bar) gave higher concentrations than LC/MS method (solid bar) for tetracyclines in soil
Aga, D. S.; O'Connor, S.; Ensley, S.; Payero, J. O.; Snow, D.; Tarkalson, D., Determination of the Persistence of Tetracycline Antibiotics and Their Degradates in Manure-Amended Soil Using Enzyme-Linked ImmunosorbentAssay and Liquid Chromatography−Mass Spectrometry. Journal of Agricultural
and Food Chemistry 2005, 53, (18), 7165-7171.
Sample Preparation and Clean up
Sample ACN/water
SOLIDS: Lyophilize, pulverize, sonicate with organic solvent
Interference from Co-extracted Matrix
Avoiding “false positives” using tandem mass spectrometry
Batt, A. L.; Aga, D. S., Simultaneous analysis of multiple classes of antibiotics by ion trap LC/MS/MS for
assessing surface water and groundwater contamination. Analytical Chemistry 2005, 77 (9), 2940-2947.
C. Erythromycin-H2O
Spiked Distilled Water
D. Fredonia
Waste Water Effluent
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28Time (min)
05
10152025303540455055606570758085
9095
100
Rela
tive A
bundance
440 460 480 500 520 540 560 580 600 620 640 660 680 700 720 740 760 780 800m/z
05
10152025303540455055606570758085
9095
100R
ela
tive A
bundance
653.6
678.6
716.6
568.0
669.5 706.1473.8448.3 492.6 582.4
650.1642.4
528.7 618.7 698.5680.3
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28Time (min)
05
10152025303540455055
606570758085
9095
100
Rela
tive A
bundance
440 460 480 500 520 540 560 580 600 620 640 660 680 700 720 740 760 780 800
m/z
05
10152025
3035404550556065707580859095
100
Rela
tive A
bundance
522.0
558.4
557.5624.3540.6
715.4
m/z 716 522, 558[M-H2O+H]+ = m/z 716 24.6
24.6
9
Sample Collection: Which samples are important?