Dispersive liquid–liquid microextraction of lead(II) as 5-(4-dimethylaminobenzylidene) rhodanine chelates from food and water samples Zeid A. Alothman & Nora H. Al-Shaalan & Mohamed A. Habila & Yunus E. Unsal & Mustafa Tuzen & Mustafa Soylak Received: 4 July 2014 /Accepted: 10 November 2014 /Published online: 25 January 2015 # Springer International Publishing Switzerland 2015 Abstract A dispersive liquid–liquid microextraction pro- cedure for lead(II) as its 5-(4-dimethylaminobenzylidene) rhodanine complex has been established prior to its microsampling flame atomic absorption spectromet- ric determination. The influences of various analytical parameters including pH, solvent type and volume, dispersive solvent type and volume, 5-(4- dimethylaminobenzylidene) rhodanine amount, salt effect, and centrifugation time and speed were inves- tigated. The effects of certain alkali, alkaline earth, and transition metal ions on the quantitative extrac- tion of lead(II) were also studied. Quantitative recov- eries were obtained at pH 6. The enrichment factor was calculated as 125. The detection limit for lead is 1.1 μg/L. The accuracy of the method was tested with the additions recovery test and analysis of the standard reference materials (SPS-WW2 waste water, NIST SRM 1515 apple leaves, and TMDA-51.3 fortified water). Applications of the present procedure were tested by analyzing water and food samples. Keywords Preconcentration . Lead(II) . Dispersive liquid–liquid microextraction . 5-(4-Dimethylaminobenzylidene) rhodanine . Flame atomic absorption spectrometry . Food Introduction Lead is easy to extract and easy to work with, and because it is a commonly found metal, it has been widely used for thousands of years. Lead is found in the solar atmosphere and is abundant in the environ- ment. Lead is mainly located in mines with zinc, silver, and copper and is separated together with these metals. Lead production and consumption is increasing world- wide. It is a highly toxic metal when inhaled or ingested and is extremely harmful to human body systems and organs (Tuzen and Soylak 2007; Alexander et al. 2013; Molina et al. 2014). The main target of lead toxicity in adults and children is the nervous system. Lead toxicity, especially in middle-aged and elderly people, causes an increase in blood pressure and anemia. High levels of lead in adults and children can result in serious damage to the brain and kidneys and cause death. Furthermore, high levels of lead toxicity can cause miscarriages in pregnant women (Matthew et al. 1996; Jandyra et al. Environ Monit Assess (2015) 187: 9 DOI 10.1007/s10661-014-4160-4 Z. A. Alothman : M. A. Habila Advanced Materials Research Chair, Chemistry Department, College of Science, King Saud University, Riyadh 11451, Kingdom of Saudi Arabia N. H. Al-Shaalan Department of Chemistry, College of Science, Princess Nora Bint Abdul Rahman University, Riyadh, Kingdom of Saudi Arabia Y. E. Unsal : M. Tuzen Gaziosmanpasa University, Faculty of Science and Arts, Chemistry Department, 60250 Tokat, Turkey M. Soylak (*) Erciyes University, Fen Fakultesi, Department of Chemistry, 38039 Kayseri, Turkey e-mail: msoylak@gmail.com