Multisyringe flow injection analysis of stable and radioactive yttrium in water and biological samples

A novel multisyringe flow injection (MSFIA) method for the determination of stable and radioactive yttrium by means of a liquid-liquid extraction has been developed. An on-line column containing di-2-ethylhexylphosphoric acid (HDEHP) - a highly selective extractant for the analyte - adsorbed on a C18 support is employed to carry out the isolation from the matrix. Stable and radioactive yttrium concentrations are determined by inductively coupled plasma-atomic emission spectroscopy (ICP-AES) and by a low background proportional counter, respectively. The proposed method shows important advantages because the manual handling of radioactive samples is avoided and throughput is increased. Moreover, as the extractant can be reused, cost per analysis and waste generation are reduced. The lower limit of detection (LLD) of stable yttrium is 10 μg l-1, whereas for 90Y is 0.05 Bq. The automated isolation process yields a yttrium recovery close to 100% with a relative standard deviation of 2.3% (n = 10). Our methodology has been successfully applied to different spiked water and biological samples