|Newman, David - North Dakota State University|
|Larsen, Steven - National Pork Board|
Submitted to: American Chemical Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 3/18/2013
Publication Date: 9/8/2013
Citation: Lupton, S.J., Shelver, W.L., Newman, D.J., Larsen, S., Smith, D.J. 2013. Determination of penicillin-G procaine in kidney, muscle, serum, and urine of heavy sows after intramuscular administration [abstract]. 246th American Chemical Society National Meeting. September 8-12, 2013. Indianapolis, IN. http://acselb-529643017.us-west-2.elb.amazonaws.com/chem/246nm/program/view.php?obj_id=205253&terms=.
Technical Abstract: The United States Department of Agriculture Food Safety and Inspection Service (FSIS) recently adapted the use of the Charm Kidney Inhibition Swab (KIS) test for screening antibiotics on-site, along with a LC-MS/MS method for confirmation of KIS-positive samples. A study with 126 heavy sows (227.0 +/- 30.8 kg) dosed intramuscularly with penicillin-G procaine at 5x the label dose (33,000 U/kg bw) for 3 consecutive days using 3 administration patterns was completed to determine if the 15-day withdrawal period recommended by Food Animal Residue Avoidance Databank (FARAD) is sufficient for swine. Urine and serum were tested to determine if they could be an alternative for ante mortem screening. Sows were slaughtered at 5, 10, 15, 20, 25, 32, or 39 withdrawal days and samples collected (muscle, kidney, urine, and serum). Tissues were first screened for penicillin-G residues using the KIS test and then penicillin-G residues were confirmed by LC-MS/MS following the FSIS method CLC-BLAC.03 and a modified method from an unpublished report by M. Apley. Method limits of quantification are 6.1 ng/g, 2.4 ng/g, 4.1 ng/mL, and 5.0 ng/mL for kidney, muscle, urine and, serum, respectively. Method limits of detection are 1.8 ng/g, 0.7 ng/g, 1.1 ng/mL and 1.5 ng/mL for kidney, muscle, urine, and serum, respectively. Skeletal muscle residues depleted most rapidly, whereas kidney and urine residues depleted slower. The residue data from the skeletal muscle supports the 15-day withdrawal period recommended by FARAD, however the kidney data suggests a longer withdrawal period is needed. Kidney is the more appropriate on-site tissue to screen for penicillin-G residues than muscle; urine is appropriate for pre-slaughter screening for penicillin-G residues. Collectively, the data suggest that a 15-day withdrawal period for penicillin-G treated sows could be followed provided that kidneys are excluded from human consumption.