Aminoglycosides detection

Absorption of antimicrobial agents, influencing factors, 15 Acidophilin, food preservative, 94,95t Agglutination application, 150 description, 149-150 American foulbrood control oxytetracycline, 36-45 sulfathiazole, 36,37f Amikacin, use in food animals, 19 Aminoglycoside detection, by... 

Aminoglycoside antibiotics and / -substituted indoles are stained red. Pyrrole derivatives with free / -positions react at room temperature to yield blue-colored zones [11]. Exposure to the vapors of aqua regia deepens the colors. This reaction sometimes produces fluorescence [3]. The detection limit for monomethylhydrazine is 200 pg per chromatogram zone [3]. 

Ackermans, M. T., Everaerts, F. M., and Beckers, J. L. (1992). Determination of aminoglycoside antibiotics in pharmaceuticals by capillary zone electrophoresis with indirect UV detection coupled with micellar electrokinetic capillary chromatography.. Chromatogr. 606, 229—235. 

Liu, H., and Sunderland, V. B. (2004). Determination of sulfate in aminoglycoside antibiotics by capillary electrophoresis with indirect UV detection. J. Liq. Chromatogr. Related Technol. 27, 677—6S7. 

Although a number of chromatographic methods have been reported for determinations of aminoglycoside antibiotics in blood serum and urine, the application of chromatographic methods to residue analysis has been very limited. Shaikh et al (93) recently described an HPLC method for neomycin in animal tissue, and Lachatre et al (94) described a method for nine aminoglycosides in plasma, urine, and renal cortex tissue. Both procedures use post column derivatization with a-pthalaldehyde and fluorescence detection. 

In Australia, the general antimicrobial screen is performed on kidney and is able to detect -lactam, aminoglycoside, tetracycline, and macrolide antimicrobials and to identify the class of antimicrobial compound present. Where the screen test identifies a class of compounds, confirmation and quantitation are done by the specific HPLC or gas chromatographic (GC) method appropriate for the class of antimicrobial. 

Both ISP-MS in the SIM mode and pulsed amperometric detection were found to be suitable for the determination of aminoglycoside antibiotics in bovine tissues (124). Various stationary and mobile phases, and several ion-pairing reagents, were examined for efficient LC separation and optimum LC-MS sensitivity. 

Since 1974, Bacillus subtilis EGA has been officially employed as the test organism in the German Hemmstoff test to detect residues of tetracyclines, -lactams and aminoglycosides in kidney and muscle tissues with high sensitivity (72). Macrolides can be also detected, but to a lesser extent, whereas chloramphenicol and sulfonamides are difficult to detect. For better detection of sulfonamides, a modification of this test, the German three-plate inhibition test, was developed. This test is based on the same test organism but uses three pH values (6, 8, and 7.2), with the addition of trimethoprim. The pH relationship between the three... 

The four-plate test was initially based on the German Hemmstoff-test with an additional plate of Sarcina lulea at pH 8.0, designed for the detection of lower levels of macrolides, and a fourth plate of Escherichia coli at pH 7.2 for the detection of sulfonamides (74,75). The modified version adopted by the European Community for screening carcasses is based on three plates with Bacillus subtilis BGA at pH values of 6.0, 8.0, and 7.2 with added trimethoprim, respectively, and a fourth plate with Micrococcus luteus NCTC 8340 at pH 8.0 (74). This test as described elsewhere (76) is intended to detect residues of -lactams, tetracyclines, aminoglycosides, sulfonamides, and macrolides in muscle tissue of slaughtered animals, without any prior extraction or cleanup. 

The NKDT test is sensitive to residues of -lactams, tetracyclines, and macrolides. It is more sensitive to sulfonamides than the German three-plate test or the EU four-plate test, but it is relatively insensitive to aminoglycosides. With respect to MRLs set for liver or kidney, the NKDT is too insensitive for aminoglycosides, sulfonamides, and macrolides. One analyst can complete 150-200 tests per day. Due to the high ratio of residue levels in preurine and muscle, a negative result of this test implies that residue levels in muscle are below the limit of detection. 

Electrochemical detection has also been suggested for determination of underivatized aminoglycosides in edible animal products (3, 19), while laser-based polarimetric detection has also been used in the analysis of underivatized gentamicin in milk (9). Liquid chromatography combined with mass spectrometry... 

Aminoglycoside drugs such as gentamycin may show toxic effects in which organs Describe how these toxic effects may be detected. 

Aminoglycosides are basic, thermally labile, hydrophilic compounds that do not contain analytically useful UV-absorbing chromophores. Therefore pre- or postcolumn derivatization is necessary for their UV or fluorescence detection. 

J. A. Polta, D. C. Johnson, and K. E. Merkel, Liquid chromatographic separation of aminoglycosides with pulsed amperometric detection, J. Chromatogr., 524 407-414 (1985). 

Derivatization is the preferred option for aminoacids (making use of the anomalous ORD or CD effects introduced with the chromophore) to move the Cotton bands to longer wavelengths and to lower the limits of detection. Derivatizations might include N-acetylation as in the case of aminoglycosides [67], dansylation [72], or binding to metal complexes [73,74], see later. On the other hand aminoacids have an auxiliary role to play in the analysis of other substances, where advantage is taken of their chiroptical properties. 

---