This paper reports on the determination and distribution of antibiotic drugs in
poultry feeds mainly the layers and growers mash obtained from Ogun state in
Nigeria. Pulverized feed samples were initially treated with phosphate buffer
adjusted to pH 7 and the analytes extracted in an SPE cartridge with ammonium
hydroxide and methanol. The extract reconstituted in phosphate buffer was
determined with high-performance liquid chromatography-diode array detection
(HPLC–DAD). The analytical column was an XTerra MS C18 column, (4.6 mm x
100 mm, 3.5 μm) with mobile phases consisting of ultrapure water and acetonitrile
mixed with 0.1% HCOOH in gradient elution mode. Data acquisition was achieved
with AgilentChemStation Version B.040.01 SP1 while the analytes were
completely separated under 10 minutes with good resolution and symmetric peaks.
The high correlation coefficient (R2) values (> 0.998, excluding sulfadimethoxine)
indicate a good correlation between analyte concentration and peak areas. Limit of
detection (LOD) and quantitation (LOQ) was between 5.37 and 55.42 ng/g, and
17.91 and 184.74 ng/g, respectively. All the drugs exhibited high mean
concentration values in the two feed types, and there was no significant difference
between their means (p < 0.05). The results clearly showed that feed millers fortify
their feeds with antibiotics mainly sulfonamides in varying amounts without
declaring same, thus compromising security of poultry birds and human consumers