Feed Additives, Colorimetric Determination of Procaine Penicillin in Premixes

Abstract

The test for Amprol cannot be run directly on the finished feed.It is necessary to extract the compound with 65% methanol and filter the extract.In general, the dimethylformamidesodium methylate test was most satisfactory as a field procedure for detection of Zoamix in either premixes or finished feed. The reagents are very stable and can be used for long periods of time.The sodium methylate test was therefore adapted to the determination of the distribution of Zoamix in the finished feed.In the preparation of Zoamix, the chemical is coated on small particles of soybean meal.When the meal is mixed with the other feed ingredients, these particles are distributed throughout the feed. When a small quantity of the feed is spread uniformly between two pieces of filter paper and is pressed on a pad moist with dimethylformamide and sodium methylate, the compound appears as green areas.The color is transferred to the paper when pressure is exerted on the system, and visual indication of the distribution of Zoamix is obtained (Figure 2). This test is simple to operate and the equipment-i.e., Petri dishes, test tubes, etc.-can be used over and over again by simply washing and drying it between each test. This pro-cedure has been employed to study the distribution of Zoamix in various lots of commercially prepared feed and has been very helpful in determining when the sample is well mixed. Literature Cited(1) Schulz, E. P., Szalkowski. C. R.,

Automated colorimetric determination of penicillin in fermentation samples using a molybdoarsenic acid-mercuric chloride reagent

“…F: The penicillinase reagent (Penase Leo) contains 100,000 Leo units of enzyme in one liter of phosphate buffer pH 7.5. This can be stored up to 5 days by being kept in a brown bottle at room temperature.…”

“…Green and Monk (4) developed an automated methodology based on Pan's original method. Katz and Winnett 1962 (5) and Katz (6) used Pan's method for analyzing procaine penicillin contained in premixes and mixed feeds by extracting with methanol. Stone (7) employed a new extracting material, chloroform dimethyl formamide, for the determination of procaine penicillin in mixed feeds.…”

“…( 4) T. G. Whiston and G. W. Cherry, Analyst, 87, 819 (1962). chloranilic acid scheme (5) presents temperature, time, and pH as critical variables and suffers from serious interferences by citrate and tartrate. The systems utilizing scandium(III)monochromium Bordeaux C and zirconium(IV)-2-carboxybenzene-3,4-dihydroxybenzene (6) are subject to numerous interferences.…”