Lead in collyrium and silver foils by absorbance modification, stability of lead thymol blue complex and comparison of different methodsAuthor(s): Khalid Hussain, Syed Saeed Ul Hassan, Noor Jahan, Syed Atif Raza, Abida Latif
This studywas undertaken to investigate collyriumand silver foils for lead contents by using an absorbance modification technique(Visible spectroscopy) and its comparison with gravimetry and atomic absorption spectroscopy. Lead-thymol blue complex was studied for stability with reference to(pH, temperature, time and concentration) and the interference of ionic impurities(silver, ferrous, zinc, copper, aluminum, magnesium and cadmium) on lead recovery. Both collyrium and silver foil samples were found to contain lead in different concentration. Lead thymol blue complex was found to be stable at pH 1 and temperature below800C for 30minutes. Aluminum, ferrous and zinc do not interfere at concentration 10ïg/mlwhile others interfere at this level. The lead contents by visible spectroscopy were similar to atomic absorption spectroscopy(P<0.05). Thismethod can be used for routine analysis of lead contents. The use of collyrium and silver foils can contribute in lead toxicity.