title: Screen-printed electrode based electrochemical detector coupled with ionic liquid dispersive liquid-liquid microextraction and microvolume back-extraction for determination of mercury in water samples.
abstract: A novel approach is presented, whereby gold nanostructured screen-printed carbon electrodes (SPCnAuEs) are combined with in-situ ionic liquid formation dispersive liquid-liquid microextraction (in-situ IL-DLLME) and microvolume back-extraction for the determination of mercury in water samples. In-situ IL-DLLME is based on a simple metathesis reaction between a water-miscible IL and a salt to form a water-immiscible IL into sample solution. Mercury complex with ammonium pyrrolidinedithiocarbamate is extracted from sample solution into the water-immiscible IL formed in-situ. Then, an ultrasound-assisted procedure is employed to back-extract the mercury into 10 µL of a 4 M HCl aqueous solution, which is finally analyzed using SPCnAuEs. Sample preparation methodology was optimized using a multivariate optimization strategy. Under optimized conditions, a linear range between 0.5 and 10 µg L(-1) was obtained with a correlation coefficient of 0.997 for six calibration points. The limit of detection obtained was 0.2 µg L(-1), which is lower than the threshold value established by the Environmental Protection Agency and European Union (i.e., 2 µg L(-1) and 1 µg L(-1), respectively). The repeatability of the proposed method was evaluated at two different spiking levels (3 and 10 µg L(-1)) and a coefficient of variation of 13% was obtained in both cases. The performance of the proposed methodology was evaluated in real-world water samples including tap water, bottled water, river water and industrial wastewater. Relative recoveries between 95% and 108% were obtained.
authors: Departamento de Química Analítica, Nutrición y Bromatología e Instituto Universitario de Materiales, Universidad de Alicante, P.O. Box 99, E-03080 Alicante, Spain.
authors: Elena
authors: E
authors: Fernández
authors: Departamento de Química Analítica, Nutrición y Bromatología e Instituto Universitario de Materiales, Universidad de Alicante, P.O. Box 99, E-03080 Alicante, Spain. Electronic address: lorena.vidal@ua.es.
authors: Lorena
authors: L
authors: Vidal
authors: Departamento de Química Física y Analítica, Universidad de Oviedo, C/Julián Clavería, 8, 33006 Oviedo, Spain.
authors: Daniel
authors: D
authors: Martín-Yerga
authors: Departamento de Química Física y Analítica, Universidad de Oviedo, C/Julián Clavería, 8, 33006 Oviedo, Spain.
authors: María del Carmen
authors: Mdel C
authors: Blanco
authors: Departamento de Química Analítica, Nutrición y Bromatología e Instituto Universitario de Materiales, Universidad de Alicante, P.O. Box 99, E-03080 Alicante, Spain. Electronic address: a.canals@ua.es.
authors: Antonio
authors: A
authors: Canals
authors: Departamento de Química Física y Analítica, Universidad de Oviedo, C/Julián Clavería, 8, 33006 Oviedo, Spain.
authors: Agustín
authors: A
authors: Costa-García
mesh_terms: D001881:Borates / Q000737:chemistry; D002244:Carbon / Q000737:chemistry; D002614:Chelating Agents / Q000737:chemistry; D060766:Drinking Water / Q000032:analysis; D055664:Electrochemical Techniques / Q000295:instrumentation; D004566:Electrodes; D006046:Gold / Q000737:chemistry; D007093:Imidazoles / Q000737:chemistry; D007094:Imides / Q000737:chemistry; D059627:Liquid Phase Microextraction; D018020:Lithium Compounds / Q000737:chemistry; D008628:Mercury / Q000032:analysis* / Q000737:chemistry; D008900:Mineral Waters / Q000032:analysis; D049329:Nanostructures / Q000737:chemistry; D011759:Pyrrolidines / Q000737:chemistry; D045483:Rivers / Q000737:chemistry; D013859:Thiocarbamates / Q000737:chemistry; D062065:Wastewater / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry
chemical_list: D001881:Borates; D002244:Carbon; D002614:Chelating Agents; D060766:Drinking Water; D006046:Gold; D007093:Imidazoles; D007094:Imides; D018020:Lithium Compounds; D008628:Mercury; D008900:Mineral Waters; D011759:Pyrrolidines; D013859:Thiocarbamates; D062065:Wastewater; D014874:Water Pollutants, Chemical; C528767:1-hexyl-3-methylimidazolium; C020972:pyrrolidine dithiocarbamic acid
keywords: Dispersive liquid–liquid microextraction; Ionic liquid; Liquid-phase microextraction; Mercury; Screen-printed electrode; Water samples