β-Correction spectrophotometric determination of mercury and its complex-ratio with malachite green

Abstract

Mercury has been determined by β-correction spectrophotometry using both malachite green (MG) and iodide. This method eliminates completely the effect of excess MG giving real absorbance of the chelate formed between Hg(II) and MG. The sensitivity, precision and accuracy are higher as compared to those obtained by the single wavelength method. With β-correction spectrophotometry the complex formation ratio of MG : Hg(ll) can be determined accurately and was found to be 3. Results show that Beer’s law is obeyed over the concentration range 0-1.60 mg/L Hg(II) with the detection limit of 0.004 mg/L. The analysis to practical samples results that the recovery of mercury is between 90.0 and 105% with the RSDs less than 5.1%. This method has been applied for the analysis of environmental water.