Spectrochemical determination of trace uranium by an argon-stabilized U-shaped DC arc

An argon-stabilized U-shaped DC arc with the system for aerosol introduction was used for uranium determination. High uranium toxicity suggests the necessity of developing as sensitive methods as possible for U detection in various natural samples and complex matrices. By optimizing the operation conditions of U-shaped arc plasma and by applying an appropriate computer program that performs temporal integration of recorded signals, the measurement precision as well as the concentration sensitivity were improved, and the detection limit was lowered. Uranium detection limit, obtained by the application of U-shaped arc plasma during different integration times, decreases by increasing integration time. By increasing this time from 1 to 30 s, the detection limit was 37 times lower and the lowest detection limit is 0.07 μg/mL. The detection limit achieved by this method is comparable with the detection limits obtained by such methods as inductively coupled plasma-atomic emission spectroscopy (ICP-AES), direct coupled plasma-atomic emission spectroscopy (DCP-AES), and microwave induced plasma-atomic emission spectroscopy (MIP-AES).