Rapid Identification Of Heavy Metals And Rapid Determination Of Cu Cr(Ⅵ) Ni Ions In Sudden Water Pollution

Heavy metals are widely used in industrial production, sudden water pollution willbe easily caused if these heavy metals can’t be effectively disposed, besides,environment and human health will also be harmed. So it is very important to establishrapid identification and determination methods of heavy metals.In this paper, rapid identification method and rapid identification kit of the heavymetals were studied. When analyzing water samples,0.2mL0.08%zinc reagent and1.0mL Boric acid-KCl-NaOH buffer solution were used. Under this condition, Cu(II)、Zn(II)、Ni(II)、 Pb(II)、Co(II)、Mn(II) could react with zinc reagent, blue, blue,pink-gray, rose-red, blue-green and yellow-green colors were showed, the detectionlimit of these metals were found to be2mg/L、1mg/L、1mg/L、2mg/L、1mg/L、0.5mg/L. Dicyclohexanoneoxaly dihydrazone(BCO) could be used to separate Cu andZn, blue complex would be got when BCO reacted with copper, but BCO couldn’t reactwith zinc. The detection limit of Cu was found to be0.5mg/L. IfDiphenylcarbazide(DPC) was added to the water and mulberry phenomenon wasshowed, water was considered to be polluted by Cr(VI), the detection limit was found tobe0.05mg/L.Based on spectrophotometry, rapid determination methods of Cu(II)、Cr(VI) andNi(II) were established, combined with a portable spectrophotometer, these emergentrapid determination methods could be used in sudden water pollution.In order to determinate the Cu(II) in water, the copper ion rapid detection kit wasdeveloped, including2g/L of BCO as reagent A,1mL mixture of NH4Cl-NH3.H2O andammonium citrate as reagent B. Complex’s test wavelength was deceded to be600nmwith its chromogenic time at10min. The linear correlation of this method was obeyedin the concentration range of0.015-5.000mg/L. The regression equation was found tobe A=0.2595C+0.0028，the linear correlation coefficient was0.9999, and the detectionlimit was0.015mg/L. Actual water samples were analyzed, comparing with nationalstandard method, the relative error of the result was showed less than10%. The regentscould steadily exist for at least20days.DPC was used to achieve the rapid detection of Cr(VI), in the rapid detection kit,(1+7)H2SO4was reagent A,0.04g DPC-NaCl mixed powder of which the mass ratiowas1:20was reagent B. The chromogenic time and test wavelength were identified as5 min and540nm. The detection limit was0.015mg/L. Beer’s law was obeyed in theconcentration range of0.005-1.000mg/L. The regression equation was found to beA=0.6093C+0.0066and the linear correlation coefficient was0.9997. Reagents could bestored for at least two months, only10min was spent to test a water sample.When preparing the rapid detection kit of Ni(II),0.05g ammonium persulphatewas used as reagent A,3mL mixture of dimethylglyoxime alkaline solution and sodiumtartrate was used as reagent B. The linear correlation of this method was obeyed in theconcentration range of0.028-4.000mg/L. The test wavelength was identified as470nm,The regression equation was found to be A=0.2341C+0.02，the linear correlationcoefficient was0.9998. The detection limit was calculated as0.015mg/L. Actual watersamples were both analyzed by this method and ICP-AES method, the relative error ofthe result was showed less than5%. If under dark conditions, the reagents wereconsidered to be stable for at least20days.