Flow Injection Analysis of Feed and Premix for Monensin and Salinomycin

Abstract

and salinomycin, which are produced by Streptomyces, are widely used as additives in broiler feed and cattle feed. However, at a certain level, these antibiotics are toxic. For the quality control of feed and premix it is thus very important to monitor the concentrations of these antibiotics. At present, colorimetric methods are widely used for this purpose, but they are rather time-consuming. The present paper describes the application of colorimetric methods to flow injection analysis (FIA) of these antibiotics. The established method facilitates the rapid analysis of feed and premix for the quality checking.

Theoretical Analysis Concerning the Characteristics of a Dye-binding Method for Determining Serum Protein Based on Protein Error of pH Indicator: Effect of Buffer Concentration of the Color Reagent on the Color Development

“…In this study, an analysis of the protein error was performed in the same manner as in previous studies, [6][7][8][9] adding one more assumption that the anion contained in the buffer solution like the dissociated dye anion also reacts with protein, forming a anion-protein complex which is a colorless substance. The next chemical equilibria are assumed to exist in the test solution:…”

“…The author previously revealed that the spectral characteristics of the sulfonephthalein pH indicators observed in the presence of protein can be explained by the chemical equilibrium based on the reaction between the side chains of the amino acid residue positively charged in a protein molecule and the dissociated dye anion. 6 In addition, it was found that the characteristic of the calibration curve depends on the pH and the dye concentration of the color reagent, 7,8 and that the upper limit pH value where the absorbance increase appears is decided by the ratio between the absorptivities of the dissociated dye anion and the dye-protein complex. 9 In designing a dye-binding method using a pH indicator, in order to establish a reliable method, it is important to know the factors which affect the color development, and to select proper measurement conditions under which analytical errors are hard to develop.…”

Improvement of chemical analysis of antibiotics. 21. Simultaneous determination of three polyether antibiotics in feeds using high-performance liquid chromatography with fluorescence detection

“…A typical chemical analysis for SL and MN is a colorimetry in which vanillin is used as a reagent to form a colored complex with these compounds. The reaction mechanism was first proposed by Duke in 1947. It has not been completely understood yet, but vanillin has been frequently used for feed analysis using colorimetry (Golab et al, 1973; Kono and Yamamoto, 1979;Marten, 1982;Kozak, 1984;Suhara, 1986;Oyama, 1986;Illing and Mueller, 1986; Sokolic and Pokorny, 1991), spectrodensitometric methods (Koufidis, 1976;Owles, 1984; Kovacs-Hadady and Kupas, 1984), and flow injection analysis (Suzuki et al, 1987). These methods are not suitable in feed analysis, because Suhara (1986) and Oyama (1986) reported that the blank values determined by colorimetry were 4 and 1.8-5.6 ppm for SL and MN in various feeds, respectively.…”