A Simple Pre-concentration Method for the Determination of Nickel(II) in Urine Samples Using UV-Vis Spectrophotometry and Flame Atomic Absorption Spectrometry Techniques

Ahmed Fadhil Khudhair (Department of Chemistry, College of Science, University of Kerbala, Karbala, Iraq)
Mouyed Khudhair Hassan (Oil Products Distribution Company (Kerbala), Ministry of Oil, Iraq)
Hasan F. Alesary (Department of Chemistry, College of Science, University of Kerbala, Karbala, Iraq)
Ahmed S. Abbas (Department of Chemistry, College of Science, University of Babylon, Babylon, Iraq)

Indonesian Journal of Chemistry
Vol 19, No 3 (2019)

The cloud point technique was effectively utilized for extraction and pre-concentration of nickel(II) in urine samples before measurement by UV-Vis spectrophotometer and AAS techniques. The metal response to a para-aminophenol (PAP) reagent in a non-ionic surfactant Triton X-114 medium was to form the Ni-PAP complex. The adopted concentration for PAP, concentration of Triton X-114, pH effect and water bath temperature, incubation time, salt effect, and interference effects were all optimized. The calibration curve was linear over the range of (0.0625–1.25) mg L–1 with a correlation coefficient r2 of 0.9682 for the UV-Vis spectrophotometer at a λmax of 629 nm. The limit of detection was 0.005 mg/L. The relative standard deviation for six replicates was 1.07%. This method was applied successfully to determine copper (II) concentrations in 44 urine samples of occupational worker samples as determined by UV-Vis spectrophotometry and FAAS techniques.