Determination of uranium in the ash of plants and its precision [report]

1956 unpublished
In the routine fluorimetrie procedure of the U, S* Geological Survey for the determination of uranium in the ash of plants, over 99 percent of the determinations during the past %year fall in the range Q.^ to 50 ppm* The method uses a simple nitric acid leach for solution of the ashed sample, Elements that wuld interfere are eliminated by extracting uranium present with ethyl acetate after addition of aluminum nitrate as a salting agent. The extracted uranium is fused with a fluoride-carbonate
more » ... lux, and the intensity of fluorescence produced in the cooled melt by ultraviolet light is measured in a transmission fluorimeter. The precision of results in the range from 0.^ to 35 ppa uranium in plant ash is expressed by a simple equation (standard deviation = 0*063 U 0*15, where U is the observed uranium concentration in parts per million)* This equation is based on 319 pairs of determinations, made during a period of about a year, on samples consisting of ash from sage brush, pinon pine, ponderosa pine, and juniper*
doi:10.3133/tei654 fatcat:qky3hzsprreezfhgkdwrtg2rdq