Updated determination of trace amounts of zinc with dibromo-O-nitrophenylflurone by primary-secondary wavelength spectrophotometry

The reaction between zinc (Zn2+) and dibromo-o-nitrophenylflurone (DBNPF) w as studied at pH 9. It was sensitive and selective in the presence of fluor ide and triethanolamine. Due to the effect of excess DBNPF, the new method named as primary-secondary wavelength spectrophotometry (PSWS) was applied instead of ordinary spectrophotometry for the determination of trace amount s of zinc. Results showed that such a method resulted in a better precision and higher accuracy than the ordinary method. By analyzing several samples , the relative standard deviations were less than 7.8% and the recovery rat e of Zn between 93.3 and 110%.