Determination of trace antimony(III)by reverse flow injection inhibitory kinetic spectrophotometry

A new FI inhibitory kinetic spectrophotometric method using the redox reaction between potassium bromate and 2-[2′-(5-Nitro-pyridylazo)]chromotropic acid(5-NO2-PACA)is proposed for the determination of trace antimony(III).In phosphoric acid medium and reaction temperature at 50℃,the linear range is 0~0.36μg·mL-1 and the detection limit is 9.6×10-6g·L-1.The relative standard deviation is 0.59%.20.2 samples can be analysed per hour.Combined with the ASS,the method has been applied to the determination of trace antimony(III)in the samples of natural waters.The comparison and recovery tests have also been carried out,and satisfactory results are obtained.