A portable photoelectric method for the rapid determination of Pb~(+2) and Cr~(+6)

Objective:To establish a rapid and quantitative method for the determination of Pb+2 and Cr+6 in samples on the spot by the testing agent combining with a portable photolometer.Methods: In acidic condition,Cr+6 can react with diphenyl carbohydrazide and generate one kind of purple complex compound(max=544 nm).In alkaline condition,Pb+2 can react with salicylflyuorene and generate ternary complexes(max=560 nm).There is a good linear relationship between the shades of the compound′s color and the concentration of Pb+2/ Cr+6 which could be quantitatively determined by portable photolometer.Results: The linear working range of Pb+2 was 0.0～10.0 mg/L(r=0.9959) with the detection limit of 0.5 μg and the recovery was 75%～88% respectively.And the linear working range of Cr+6 was 0.0～2.0 mg/L(r=0.9970) with the detection limit of 0.2 μg and the recovery was 88%～101%.Conclusion: By means of fixing the chromogenic reagent on the scrip which substituted the detection reagent in the operation,the detection of Cr+6 is more convenient.This method reagents combined with portable photolometer for the determination of Pb+2 and Cr+6 is simple,rapid and suitable for the quantitative field detection and worth of application and extension.