Facile and selective determination of the cerebral vasodilator nafronyl in a commercial formulation by heavy atom induced room temperature phosphorimetry.

This paper presents a facile and selective method for the determination of the pharmaceutical compound nafronyl using heavy atom induced room temperature phosphorimetry (HAI-RTP) as analytical technique. The determination was performed in potassium iodide 1.6 M and sodium sulphite 0.002 M at a measurement temperature of 20 degrees C. The phosphorescence intensity was then measured at lambda(exc) = 292 nm and lambda(em) = 524 nm. Phosphorescence was fully developed instantly, obtaining a linear concentration range between 2.7 and 250 ng ml(-1) with the detection limit of 2.7 ng ml(-1), an analytical sensitivity of 5.1 ng ml(-1) and a standard deviation of 2.17%, at a 150 ng ml (-1) concentration level. The proposed method has been satisfactorily applied to the unique Spanish commercial formulation containing nafronyl at a 100 mg level per capsule. The recovery was 108%, with a 1.7%, standard deviation of the analytical measurement. The method has been validated using standard addition methodology.