Investigating laser induced breakdown spectroscopy for estimating uranium by its hydroxide colloids in presence of large excess of LiCl-KCl/Cd

In this work, laser induced breakdown spectroscopic (LIBS) technique is utilized to estimate U in presence of large excess of lithium and potassium chloride (LiCl-KCl) or Cd mixtures. Colloidal solution of hydroxides of U, produced by adding NaOH was spread over filter paper and subjected to LIBS analysis after drying in air. Nearly 50 times enhancement in the LIBS signal was found as compared to normal solution. Using Er as an internal standard, emission line of U(II) at 385.957 nm shows linearity from 50 to 600 ppm. The detection limit of U was found to be 21 ppm. The presence of 5% LiCl-KCl salt or 3% Cd does not alter the calibration plot significantly. The estimations of U in synthetic samples agree well with the values measured by spectrophotometric method. (author)