Abstract
Optimum conditions were investigated for the turbidimetric determination of furazolidone using Escherichia coli, as the test organism, and meat extract medium.
The sensitivity of E. coli to the drug was affected by the pH of the medium, incubation period, and inoculum size. The optimum growth curve was obtained by using the medium containing 0.5per cent meat extract, 0.5 per cent pepton, 0.25 per cent sodium chloride, 2 per cent ethanol, at pH 8.0, by inoculating 3×106 cells/ml. of the test organism, and incubating for 18 hours at 37°C. By using this standard growth curve, it is possible to determine a concentration as low as about 0.05mcg/ml. of furazolidone.
When four tubes were used for one test solution, the maximum standard deviation in this method was approximately 6.5 per cent.
All the growth curves obtained of different types of nitrofuranderivatives (3 of acid amide type, each one of aminooxazolidone type, morpholinomethyloxazolidone type and oxim type) were almost the same in shape.
