Determination of trace amount of crystal violet by spectrophotometry after cloudpoint extraction

A new method for the determination of trace amount of crystal violet from aqueous solutions by spectrophotometry after cloud point extraction has been proposed. The optimum extraction and reaction conditions,such as pH,reagents concentration and effect of time and temperature,have been studied with the nonionic surfactant triton X-114.The maximum absorption wavelength of crystal violet is 579 nm.Linearity was obeyed in the range of 32～700 ng/mL with the limit of detection of 9.8 ng/mL.The enrichment factor was 20 for crystal violet.The relative standard deviations for the simultaneous determination of 8 test samples at the levels of 0.2 and 0.5 μg/mL were 2.5% and 1.7%,respectively.The proposed method was successfully applied to the determination of trace amount of crystal violet in real water samples with the recoveries of 95.2%～98.1%.