R T Teague | PubMed Health

PubMed1983

High pressure liquid chromatographic determination of carbadox and pyrantel tartrate in swine feed and supplements.

A rapid yet reliable procedure for the simultaneous extraction and assay of carbadox and pyrantel tartrate is described. The feed is extracted with water-acetonitrile-methanol and cleaned up on a short alumina column. The eluant is separated by high pressure liquid chromatography and the compounds are detected at different wavelengths. The drugs of interest are well resolved in all feeds studied. The procedure has also been applied to a wide range of feeds which contained either one of the drugs or both in combination. No significant interferences were observed. Spiked sample recoveries were 97% for carbadox and 101% for pyrantel tartrate. Ruggedness test coefficients of variation were 2.0% for carbadox and 2.1% for pyrantel tartrate.

Animal Feed↗

PubMed1981

Minicolumn detection methods for aflatoxin in raw peanuts: collaborative study.

The Holaday-Velasco method and a modified Holaday method have been compared. The former method combines the speed and simplicity of the Holaday extraction and cleanup with the sensitivity of the minicolumn originally described by Velasco. The combination method has been approved by the AOAC and the AACC for determining aflatoxin in corn. The Holaday method was modified by substituting toluene for benzene in the solvent partition, and methylene chloride for chloroform in the minicolumn development to eliminate use of hazardous solvents. The neutral alumina in the Holaday minicolumn was changed from activity V to activity III to provide a more stable column. At aflatoxin levels in raw peanuts of 13-20 ng/g, the presence of aflatoxin was missed by the modified Holaday method in 4 analyses (3 laboratories) of 42 reported. There were no misses in this contamination range by the Holaday-Velasco method. There were no misses by either method with samples containing greater than 20 ng total aflatoxins/g. Analysis of uncontaminated raw peanuts by the modified Holaday method resulted in 2 false positives of 14 reports; the Holaday-Velasco method produced no false positive reports from 15 analyses of uncontaminated peanuts. The Holaday-Velasco method was adopted official first action for peanuts.

Aflatoxins↗