title: Application of cold-induced aggregation microextraction as a fast, simple, and organic solvent-free method for the separation and preconcentration of Se(IV) in rice and various water samples.
abstract: The developed method is based on cold-induced aggregation microextraction of Se(IV) using the 1-butyl-3-methylimidazolium hexafluorophosphate ionic liquid as an extractant followed by spectrophotometry determination. The extraction of Se(IV) was performed in the presence of dithizone as the complexing agent. In this method, a very small amount of 1-butyl-3-methylimidazolium hexafluorophosphate was added to the sample solution containing Se-dithizone complex. Then, the solution was kept in a thermostated bath at 50 °C for 4 min. Subsequently, the solution was cooled in an ice bath and a cloudy solution was formed. After centrifuging, the extractant phase was analyzed using a spectrophotometric detection method. Some important parameters that might affect the extraction efficiency were optimized (HCl, 0.6 mol L(-1); dithizone, 4.0 × 10(-6) mol L(-1); ionic liquid, 100 μL). Under the optimum conditions, good linear relationship, sensitivity, and reproducibility were obtained. The limit of detection (LOD) (3Sb/m) was 1.5 μg L(-1), and the relative standard deviation (RSD) was 1.2 % for 30 μg L(-1) of Se(IV). The linear range was obtained in the range of 5-60 μg L(-1). It was satisfactory to analyze rice and various water samples.
authors.affiliation: Department of Chemistry, Payame Noor University, PO box 19395-3697, Tehran, Iran, r_rahnama@ymail.com.
authors.forename: Reyhaneh
authors.initials: R
authors.lastname: Rahnama
authors.forename: Zinat
authors.initials: Z
authors.lastname: Abed
mesh_terms: D005591:Chemical Fractionation / Q000379:methods*; D003080:Cold Temperature; D004784:Environmental Monitoring / Q000379:methods; D007093:Imidazoles / Q000737:chemistry; D057230:Limit of Detection; D012275:Oryza / Q000737:chemistry*; D015203:Reproducibility of Results; D012643:Selenium / Q000032:analysis* / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry
chemical_list: C412621:1-butyl-3-methylimidazolium hexafluorophosphate; D007093:Imidazoles; D014874:Water Pollutants, Chemical; D012643:Selenium