Analytical determination of nitrofurans

There are important indications for the use of certain nitrofurans for the prevention and cure of diseases in man and domestic animals. Recently the use of nitrofurans as an antiseptic feed additive has increased rapidly. 

Since chemical analysis of nitrofurans is indispensable their characteristic ultraviolet absorption has been recommended for assayi A6i. 

Reckendorf, Castringius and Spingler have utilized the colorimetric and spectrophotometric determination of nitrofurantoin in the urine and serum. Stone , and Puglisii have determined a trace of nitrofurantoin in milk by the colorimetric and spectrophotometric methods. Both procedures are based on the conversion of nitrofurantoin to 5-nitrofurfuraldehyde phenylhydrazone and are followed by the extraction and concentration on a chromatographic column. Final estimation depends upon development of a blue colour by the addition of hydramine base. Breinlich studied the titrimetric, spectrophotometric and chromatographic determinations of various nitrofurans and reported satisfactory results. 

Several workers studied the polarographic behaviour of nitrofurans. Nitrofurazone in animal feed has been quantitatively assayed by polaro-graphy. Polarographic assay of nitrofurans will require more basic research before it can be used on a large scale. However, the spectrophotometric assay of nitrofurantoin has been replaced by a polarographic assay in the first U.S. P. XVI supplement (U.S. Pharmacopoeia Convention, 1962). 

Taylor, Paul and Paul recognized that the nitrofurans act as electron acceptors in the presence of xanthine oxidase in all animal tissues. Other 

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