Liquid Chromatographic Monitoring of the Depletion of Carbadox and Its Metabolite Desoxycarbadox in Swine Tissues

Abstract A liquid chromatographic method was used to monitor a depletion study of carbadox (and its most important metabolite, desoxycarbadox) in young pigs fed carbadox-treated rations for 1 week. Carbadox was found in blood (20 ppb), blood serum (26 ppb), and muscle tissue 24 h after withdrawal from treated ration; residues were reduced to a trace (< 2 ppb) in 48 h, and eliminated by 72 h. Desoxycarbadox, although not detected in blood, was found in muscle (17 ppb) 24 h after withdrawal; it was reduced to 9 ppb at 48 h and to a trace by 72 h. Although no carbadox was detected in liver 24 h after withdrawal, appreciable desoxycarbadox (125 ppb) was found in liver 24 h after withdrawal; it was reduced to 17 ppb at 48 h and to a trace by 72 h. Whereas only a trace of carbadox was found in kidney 24 h after withdrawal, 186 ppb desoxycarbadox was found in kidney at 24 h, 34 ppb at 48 h, and a trace at 72 h. No metabolite of carbadox other than desoxycarbadox was found in extracts of swine tissues during this medicated feed trial, and no metabolite was found in blood extracts by using the established 'methodology. The effect of tissue storage (aging) at - 20°C on levels of the drug and its metabolite was a modest alteration of residue levels. The inadvertent use of feed adulterated with furazolidone and initially medicated with chlortetracycline, sulfamethazine, and penicillin G, did not affect the uptake of carbadox in this depletion study or interfere ) with the analytical methodology.

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Monitoring Pesticide Residues in Olive Products: Organophosphorus Insecticides in Olives and Oil

Journal of AOAC International ◽

10.1093/jaoac/77.5.1096 ◽

1994 ◽

Vol 77 (5) ◽

pp. 1096-1100 ◽

Cited By ~ 12

Author(s):

Chaido Lentza-Rizos

Keyword(s):

Chromatographic Method ◽

Monitoring Program ◽

Organophosphorus Insecticides ◽

Olive Fruit ◽

Low Concentrations ◽

Liquid Chromatographic Method ◽

Fruit Samples ◽

Maximum Residue Levels ◽

Residue Levels ◽

Liquid Chromatographic

Abstract A simple and efficient gas-liquid chromatographic method was used to screen and quantitate residues of azinphos ethyl, chlorpyrifos, diazinon, di-methoate, fenthion, fenthion sulfoxide, methi-dathion, parathion ethyl, and parathion methyl in olive fruit and olive oil. Most olive fruit samples analyzed during 1991-1992 either contained no detectable residues of the insecticides or contained low concentrations of fenthion, dimethoate, and chlorpyrifos. One sample contained fenthion sulfoxide at a level exceeding FAO/WHO Codex Ali-mentarius maximum residue levels (MRL) for total fenthion. Commercially packed oil samples either contained no detectable residues of the insecticides or contained low concentrations of fenthion, fenthion sulfoxide, and chlorpyrifos. More than half of the virgin oil samples collected from individual growers contained no detectable residues. The others contained mostly fenthion and its sulfoxide metabolite. Of the samples analyzed, 13% exceeded Codex MRL for total fenthion residues. These samples were from a monitoring program targeted at produce most likely to contain residues. Refining procedures seem to act as a decontamination technique for oil containing fenthion residues.

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Multiresidue Liquid Chromatographic Method for Determining Residues of Mono- and Dibasic Penicillins in Bovine Muscle Tissues

Journal of AOAC International ◽

10.1093/jaoac/81.6.1113 ◽

1998 ◽

Vol 81 (6) ◽

pp. 1113-1120 ◽

Cited By ~ 7

Author(s):

Joe O Boison ◽

Lily J -Y Keng

Keyword(s):

Muscle Tissue ◽

Phosphate Buffer ◽

Chromatographic Method ◽

Sodium Thiosulfate ◽

Laboratory Method ◽

Penicillin G ◽

Bovine Muscle ◽

Liquid Chromatographic Method ◽

Liquid Chromatographic

Abstract A liquid chromatographic method with UV detection at 325 nm was developed for simultaneous determination of amoxicillin, ampicillin, penicillin G, and cloxacillin residues in bovine muscle tissue as their mercaptide derivatives. The penicillins are extracted from bovine tissues with 0.1 M phosphate buffer (pH 8.5), cleaned up on a t-C18 Sep-Pak cartridge, and eluted with 2 ml acetonitrile. After the acetonitrile in the eluate is evaporated to dryness, the residue is dissolved in 200 |µL (40 + 60, v/v) aceton itrile-phosphate buffer (pH 6.5) and derivatized with acetic anhydride and mercuric chloride in the presence of 1,2,4-triazole at 65°C for 30 min. Gradient analysis on a Spherisorb 5 µm ODS(2) (octadecyl silane) analytical column using a binary mobile phase consisting of acetonitrile and 0.10M phosphate buffer (pH 6.5) in the presence of 0.0157M sodium thiosulfate at 1 mL/min permits determination of each intact penicillin in bovine muscle tissue at ≥10 ppb with recoveries ≥72%. This laboratory method provides detection sensitivities equivalent to those of rapid tests used for screening β-lactam drug residues in bovine tissue samples for regulatory enforcement.

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