Polarographic and colorimetric methods for determination of cyclophosphamide.

Polarographic and colorimetric methods for analysis of cyclophosphamide and its dosage forms were investigated. Both methods are based on the reaction of cyclophosphamide with nitrous acid. A single cathodic diffusion-controlled wave was used for dc polarographic determination of cyclophosphamide, with an accuracy of 99.98 +/- 1.09%. The wave was well defined and irreversible. By differential pulse polarographic analysis, as little as 10 ppm cyclophosphamide was determined; overall accuracy at 10-60 ppm was 100.16 +/- 0.99%. The linear relationship between absorbance for the lemon-yellow nitroso derivative and the concentration of cyclophosphamide was further used in colorimetric analysis; overall accuracy was 100.2 +/- 0.99%.