Streptomycin analysis

Li, Y. M., Debremaeker, D., Van Schepdael, A., Roets, E., and Hoogmartens, J. (2000). Simultaneous analysis of streptomycin, dihydrostreptomycin and their related substances by capillary zone electrophoresis. J. Liq. Chromatogr. Relat. Technol. 23, 2979—2990. 

Extractions traditionally have been performed using buffers (j ) the same used to obtain the maximum response in standard curves. Unfortunately this has been a major failing of the plate diffusion assay systems. It is rare that the pH can be adjusted to the optimum necessary for greatest response simply by blending a matrix with buffer. As much as a 30 to 40% loss of activity can occur by not adjusting the pH properly analysis for residues of the streptomycins and erythromycin, for example, can yield results 20% lower by having the pH of the analyte 0.2 units below 8.0 if the pH is 0.5 units below 8.0, the loss of potency approaches 50% (14-15). 

Analysis of the 1994 tissue residue data revealed that FSIS reported 2514 animals containing violative residues. FDA, in cooperation with participating states, conducted follow-up investigation on 1076 (45%) of the reported violations. The drugs most frequently identified as causing antibiotic residues included penicillin (21%), oxytetracycline (10%), sulfamethazine (10%), streptomycin (6%), tetracycline (5.2%), neomycin (4.1%), gentamicin (3.7%), and sulfadimeth-... 

In traditional electrophoresis, separation efficiency is limited by thermal diffusion and convection. Owing to long analysis times and low efficiencies, these procedures never enjoyed wide usage. Problems have arisen when trying to differentiate between structurally related drug residues such as streptomycin and dihydrostreptomycin, tetracyclines, lincomycin and clindamycin, and erythromycin and oleandomycin (83, 84). To overcome these problems, anticonvective media, such as polyacrylamide or agarose gels, have also been used. 

An indirect competitive ELISA has been also developed for the determination of streptomycin and dihydrosticptomyciri in milk (24). Prior to the analysis, the milk sample was skimmed and treated with oxalic acid. The antiserum was raised in rabbits using streptomycin linked to a bacterial protein as the antigen. To perform the test, microtiter plates were coated with streptomycin, and antiserum and milk samples were mixed to be added in the wells where they were incubated for 1 h. Depending on the amount of residues in the sample, more or less antibody remained available for binding to the streptomycin coat. A pig antirabbit antibody-enzyme conjugate was subsequently added and incubated for 90 min. Using a suitable substrate, streptomycin and dihydrostreptomycin could be detected down to 1.6 ppb, whereas quantification could be made possible up to 100 ppb when samples were used undiluted. 

Eisman and coworkers - have investigated the use of microorganisms made resistant to an antibiotic of known chemical and biological properties in order to differentiate it from an unknown antibiotic of similar bacterial spectral analysis. Strains of bacteria which have developed a high resistance to streptomycin have been used to differentiate unknown antibiotics from streptomycin. Some resistant variants have been developed which actually appear to require streptomycin for growth. ... 

The molecular formula of streptomycin was established as C2iH37 39-N7O12 by elementary analyses of the crystalline streptomycin trihydrochloride-calcium chloride double salt, of crystalline streptomycin trihelianthate and of amorphous streptomycin trihydrochloride of high purity. The composition of crystalline streptomycin reineckate was in agreement with this formula as was also the analysis of the calcium chloride double salt performed in another laboratory. ... 

With the differential pulse polarography [245], the antibiotics can be determined at low concentration, if necessary, at the ppm or even sub-ppm level. Tetracycline hydrochloride is determined in aqueous acetate buffer pH 4 (detection limit 0.1 ppm), but for the analysis of chlortetracycline hydrochloride, oxytetracycline hydrochloride and free tetracycline, a non-aqueous medium must be used. Streptomycin sulphate is analysed in alkaline solution, trace quantities of zinc being masked by Na2EDTA, and the detection limit is 1 ppm. A determination in blood serum or urine is also possible but the peak potentials are shifted here to more negative values. The polarographic determination is preceded by ultrafiltration. Penicillin G potassium and ampicillin must be first functionalised by nitrosation. The authors also recommend an analysis of mixtures which is however demonstrated only with chloramphenicol and tetracycline, at 2.4 and 4.2 ppm, respectively. 

In weak composite acrylamide-agarose gels Dahlberg et al. (1969) reported that not only ribosomes but polysomes could be made to migrate, and this provides indeed an elegant and convenient procedure for the analysis of polysome populations (Fig. 10.15). Addition of the antibiotic streptomycin which is known to bind to ribosomes, causes... 

The determination of trace metal impurities in pharmaceuticals requires a more sensitive methodology. Flame atomic absorption and emission spectroscopy have been the major tools used for this purpose. Metal contaminants such as Pb, Sb, Bi, Ag, Ba, Ni, and Sr have been identified and quantitated by these methods (59,66-68). Specific analysis is necessary for the detection of the presence of palladium in semisynthetic penicillins, where it is used as a catalyst (57), and for silicon in streptomycin (69). Furnace atomic absorption may find a significant role in the determination of known impurities, due to higher sensitivity (Table 2). Atomic absorption is used to detect quantities of known toxic substances in the blood, such as lead (70-72). If the exact impurities are not known, qualitative as well as quantitative analysis is required, and a general multielemental method such as ICP spectrometry with a rapid-scanning monochromator may be utilized. Inductively coupled plasma atomic emission spectroscopy may also be used in the analysis of biological fluids in order to detect contamination by environmental metals such as mercury (73), and to test serum and tissues for the presence of aluminum, lead, cadmium, nickel, and other trace metals (74-77). 

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