Thin Layer Chromatographic/Bioautographic Method for Identification of Antibiotic Residues in Animal Tissues

Abstract

An analytical method for the identification of the residues from 14 commonly used antibiotics is presented. The technique is based on selective tissue extraction followed by thin layer chromatography (TLC)/bioautography. Antibiotic residues are extracted from the tissues with methanol and methanol-HCl (98 + 2). The methanol extract is further extracted with chloroform to isolate groups of antibiotics. The extracts are spotted onto TLC plates and developed in suitable solvent systems. Developed plates are placed on set medium seeded with Bacillus subtilis and a bioautograph is produced. The locations of zones of inhibition are used to identify antibiotic residues. Recoveries of antibiotics were quantitative, while the effect of naturally inhibiting components of the matrix was minimized. The sensitivity of the method can be adjusted through minor modifications, which allows its use in routine regulatory analysis.

Determination of antibiotic residues in Canadian slaughter animals by thin-layer chromatography-bioautography

“…Table III lists the MDL and Rf data for standard solutions of each of the 14 antibiotics and for spiked bovine and porcine muscle and kidney. The MDLs for standard solutions were comparable to those reported for similar techniques (Neidert et al, 1987; Frerichs and Chandler, 1982;Smither and Vaughan, 1978). However, some of the MDLs for antibiotics spiked in tissues were much higher than those for standard solutions, due in part to our stringent acceptance criterion (four of four replicates producing inhibition in one run) and to what was believed to be a large variation in the recovery of these antibiotics in the presence of the tissue matrix.…”

“…Tissues from animals found positive by these tests, and tissues from animals deemed suspect after physical examination, are forwarded to our laboratory for confirmation and identification of any antibiotics present. The thin-layer chromatography-bioautography (TLCB) method used for these analyses, which tests three extracts from each sample, is based on that recently described by Neidert et al (1987). This report describes our further investigations into detection parameters and outlines the methodology as applied to a routine analytical program.…”

SÜT ÖRNEKLERİNDE KLORAMFENİKOL KALıNTıLARı

“…Radioimmunoassay ve ELİSA testi esasına dayanan enzim-linked immunosorbant yöntemleri de seçkin nitelikli ve nisbet yüksek duyarlılık özeııiklerine sahip olmakla beraber, bugün için daha çok tarama amaçlarıyla kuııamlmaktadır (3,24). Oysa etkin kolramfenikol kalıntılarına aşırı derecede duyarlı hale getiiilmiş mutant bakteri suşları kuııanımı esasına dayanan biyootografi yöntemi ile hem tarama niteliğinde denetim etkinliği gerçekleştirilirken, hem de 0.3 ppb'ye kadar düşük düzeylerdeki etkin kloramfenikol kalıntılarının varlığı ortaya çıkartılabilmektedir (8,18,24,27).…”

A comparison of three bioassay techniques for the detection of chloramphenicol residues in animal tissues

“…The STOP procedure detects the presence of microbial inhibitors but does not identify them. A more specific screening procedure for antibiotics using thin-layer chromatography/bioautography (TLCB) is currently being tested in this laboratory as a confirmatory procedure (Neidert et al, 1987). This will replace, as a confirmatory laboratory test, a microbial inhibition test (MIT) previously used for this purpose.…”

“…Thin-Layer Chromatography/Bioautography (TLCB). The method used was a modification of the method described by Neidert et al (1987). A centrifuge tube and centrifugation were used rather than a separatory funnel to separate extracts 1 and 2.…”