The determination of nanogram amounts of Chromium in urine by x-ray fluorescence spectroscopy

Nanogram amounts of chromium can be extracted as oxinate into chloform. By treatment of the chloroform layer 3 M hydrochloric acid, oxinates of other elements and excess of reagent are removed, leaving a chloroform solution of the chromium chelate only. This solution is concentrated and transferred to the top of a small brass rod acting as sample holder. The intensity of the X-ray fluorescence of the Cr Kα line is measured with curved crystal optics. Chromium amounts greater than 5 ng can be detected. The application of the procedure to the analysis of the chromium content of urine is demonstrated.