Simultaneous Determination of Mixed Heavy Metal Ions Cr (III) and Co (II) in Wastewater by Cloud Point Extraction Dual Wavelength Spectrophotometry

Using cloud point extraction technology and the principle of absorbance addition in multi-component system, the mixed metal ions Cr (III) and Co (II) in industrial wastewater were enriched and determined at pH 5.0 and 50℃, using ammonium pyrrolidine dithiocarbamate (APDC) as complexing agent and Triton X-114 as extractant. The results indicate that the contents of Cr (III) and Co (II) can be calculated using a simultaneous equation system. The detection limits for Cr (III) and Co (II) are 0.74 ng/ml and 2.12 ng/ml, respectively. The recovery rates are 95.3% -104.0% and 96.9% -103.5%, respectively. This method has the characteristics of high accuracy, good repeatability, and fast detection speed, and has good practical value.