Spectrophotometric determination of microstrontium with 4-(5-chloro-2-pyridylazo)-1,3-diaminobenzene

The color reaction of the reagent 4-(5-chloro-2-pyridylazo)1,3-diaminobenzene with Sr?in the presence of sodium dodecanesulphonate(SDS) is studied.The results show that the color reagent reacts with Sr?to form a stable yellow complex(1∶1)in the medium of HAc-NaAc buffer at pH 6.0.The maximum absorption wavelength and apparent molar absorptivity are 460 nm and 1.29×10~5 L·mol~(-1)·cm~(-1) respectively.Beer′s law is obeyed in the range of 0-12 μg/25 mL for Sr?.The method has been applied to the determination of micro-strontium? in aluminium alloy and chemical reagent with satisfactory results.