Uranium analysis using an on-line background correction program with carrier distillation technique by a computer controlled emission spectrometer

The paper describes an on-line background correction and uranium matrix excitation monitoring in a computer controlled direct reading spectrometer for the rapid estimation of a large number of impurities in uranium product used in nuclear facilities. The influence/interference of the background on the analytical lines becomes important when low detection limits are to be achieved. Commercially available softwares for automatic background correction (ABC) are suitable for inductively coupled plasma or spark sources where a continuous flow of the sample introduction is possible. However, in the case of carrier distillation technique automatic background correction cannot be applied due to limitations of exposure per charge. In the method discussed here, a background channel located at an appropriate position in the spectral range is monitored simultaneously along with other analyte channels. The background at analyte channel is computed from the intensity of the background channel and is automatically subtracted from the intensity of the analyte signal. In addition, a uranium channel which is used for monitoring a very weak line of uranium (2865.67 A) is incorporated to measure the amount of uranium getting into the arc. When intensity of uranium line exceeds the predetermined value, that data will be rejected by the operator. This method is in routine use for the estimation of 20 impurities in uranium. (author). 4 refs., 2 tabs