Separation And Enrichment With Coprecipitation Research And Application Of Heavy Metal Ions In Water By Flame Atomic Absorption Spectrometry

In this paper, the co-precipitation of Mn²⁺-phen-SCN^-, Mn²⁺-Dipy-SCN^- two ternary complex systems for copper, zinc, cadmium and lead in the water were studied. Focus on the choice of the carrier ion, co-precipitation agent to join the order, a total amount of precipitant, pH, ions and other factors on the interference effects of co-precipitation to determine the best conditions for co-precipitation. The results show that the Mn²⁺-phen-SCN^- ternary complex system shows a better concentration effect for Cu²⁺, Cd²⁺, Zn²⁺. When the concentration of Cu²⁺ is 0.01mg/L, the measured precision is 1.41% (n=11), the detection limit is 5.08μg/L (3s). The concentration of Cu²⁺ in the Taoli Lake is 4.93μg/L measured by standard addition method and the recoveries are 98%-105%. When the concentration of Zn²⁺ is 0.01mg/L, the measured precision is 2.93% (n=11), the detection limit is 3.73μg/L (3s). The concentration of Zn²⁺ in the Taoli Lake is 0.576μg/L measured by standard addition method and the recoveries are 99%-103%. When the concentration of Cd²⁺ is 0.01mg/L, the measured precision is 3.18% (n=11), the detection limit is 1.64μg/L (3s). The concentration of Cd²⁺ in the Taoli Lake is 0.618μg/L measured by standard addition method and the recoveries are 98%-101%. When the concentration of Pb²⁺ is 0.01mg/L, the measured precision is 2.27% (n=11), the detection limit is 24.2μg/L (3s). Standard addition method doesn't detect Pb²⁺ in the Xing'an League water, and the recoveries of standard addition are 98%-101%. The Mn²⁺-Dipy-SCN^- ternary complex system has a good selectivity to Cd²⁺. When the concentration of Cd²⁺ is 0.01mg/L, the measured precision is 2.83% (n=11), the detection limit is 1.91μg/L (3s ). The concentration of Zn²⁺ in the Taoli Lake is 0.630μg/L and the recoveries are 98%-101% measured by standard addition method.The Mn²⁺-phen-SCN^-, Mn²⁺-Dipy-SCN^- two ternary complex co-precipitation systems have good concentration effects for Cu²⁺, Cd²⁺, Zn²⁺ and Pb²⁺, whose enrichment factors get to 50 times, basically eliminate the matrix interference. The experimental method has high sensitivity, low detection limits, precision, recovery of trace element analysis to meet the requirements of accuracy, etc. The method provides a new way for the flame atomic absorption spectrophotometry to determinate the trace Cu²⁺, Cd²⁺, Zn²⁺, Pb²⁺and the other environment significant danger of heavy metal ions in the water, which has a certain value.