The paper describes studies carried out for the determination of U-233 at various stages during the recovery and purification of U-233 from U-233-Al alloy scraps generated during the fabrication of U-233-Al alloy fuel. Employing a high resolution sequential spectrometer and Inductively Coupled argon Plasma (ICP) as the spectral excitation source, isotope shift for U-233 with respect to U-238 has been resolved and recorded. The shift for 424.437 nm emission line of U-238 is found to be of the order of 0.040 nm on the lower wavelength side for U-233 and this isotopic effect has been utilised for the quantitative determination of U-233. The overall precision of the method is 5% RSD with the detection limit of 0.01 mu g/ml.