Rd. Caballero et al., Micellar chromatographic procedure with direct injection for the determination of sulfonamides in milk and honey samples, J LIQ CHR R, 24(1), 2001, pp. 117-131
The capability of liquid chromatography with micellar mobile phases of sodi
um dodecyl sulfate (SDS), of allowing the direct injection of biological fl
uids into reversed-phase columns, was applied to the determination of sulfo
namides in milk and honey samples. The chromatographic behavior of a group
of 15 sulfonamides was studied at pH 3.0 where the drugs showed a greater s
eparation space. Acetonitrile was added to the mobile phase to decrease the
retention of the most hydrophobic drugs and increase the efficiencies, whi
ch yielded a higher resolution. The samples were diluted with 0.10 M SDS to
facilitate the solubilization of the matrix compounds and release the prot
ein-bound drugs. The procedure is simple, rapid, and reliable, has a low co
st, and permits screening for 11 sulfonamides (sulfacetamide, sulfadiazine,
sulfadimethoxine, sulfaguanidine, sulfamerazine, sulfamonomethoxine. sulfa
nilamide, sulfapyridine, sulfaquinoxaline, sulfathiazole, and sulfisoxazole
) with good accuracy and precision. The recoveries found for milk and honey
samples spiked with 1 mug/mL of each sulfonamide, calculated from the cali
bration straight lines obtained in aqueous solution, were in the ranges 87-
108% and 72-119% for milk and honey samples, respectively. Limits of detect
ion were close to 0.1 mug/mL for sulfadiazine, sulfadimethoxine, sulfamethi
zole. sulfamonomethoxine, sulfanilamide, sulfathiazole, and sulfisoxazole i
n milk samples and sulfacetamide, sulfamethizole. sulfanilamide, and sulfap
yridine in honey samples.