Note on Benedict’s Method for Determining Total Sulphur in Urine

There has been considerable discussion on the question of determining total sulphur in urine. Folinl has suggested the use of sodium peroxide as oxidizing agent in determining total urinary sulphur. Benedict,2 by the use of copper nitrate and potassium chlorate, obtains results comparable with those of the Folin method. Ritson3 by using barium peroxide, obtains somewhat higher values than are given by the sodium peroxide method; this, however, as stated by Benedict,4 does not prove the accuracy of the method. Gill and Grindley5 have likewise obtained higher results than are given by the Folin method, but FolirP considers that the nitric acid method used by them is less reliable than the peroxide method, as described by him. The two methods which thus far have given check results are the sodium peroxide method of Folin and the copper nitrate method of Benedict. While recently engaged in making a large number of determinations of sulphur in the urines of subjects who were given various doses of sulphurous acid (eating sulphured peaches) and of sodium sulphite, using the Benedict method, the opportunity was offered not only for check determinations when the urine contained abnormally large amounts of sulphur, but also for making further comparisons with the method of fusing with sodium peroxide.