Determination of Pb in environmental water based on PbXO complex by primary-secondary wavelength spectrophotometry

The reaction between Pb2+ and xylenol orange(XO) was studied at pH 5.8 in HAc-NaAc buffer.It was sensitive and selective with the presence of sulfocarbamide and ammonium citrate.The new method named as primary-secondary wavelength spectrophotometry(PSWS) was applied instead of single-wavelength method for the determination of Pb based on the above-mentioned reaction.Results showed that such a method resulted in a good precision and high accuracy,the calculated curve was very stable.By analyzing several samples,the RSDs were less than 1.67% and the recovery rate of Pb was between 98.79%～107.6%.Within the range of 0.022～2.5 μg/L,the parameter log y was linear with log C and the DL was lower to 0.007 μg/mL.The method was suitable to be used and spreaded in departments of basement layer.