Vol.:(0123456789) 1 3 Journal of the Iranian Chemical Society https://doi.org/10.1007/s13738-018-1419-7 ORIGINAL PAPER Usage of deep eutectic solvents for the digestion and ultrasound- assisted liquid phase microextraction of copper in liver samples Gulsah Saydan Kanberoglu 1  · Erkan Yilmaz 2,3  · Mustafa Soylak 4 Received: 4 March 2018 / Accepted: 31 May 2018 © Iranian Chemical Society 2018 Abstract In this study, we used deep eutectic solvents for digestion and ultrasound-assisted emulsifcation liquid phase microextrac- tion (UA-ELPME) of copper in liver samples. Diferent types of DESs were prepared for digestion and microextraction steps. DESs consisting of lactic acid and choline chloride for the digestion step and DESs consisting of tetrabuthylamonium chloride and decanoic acid for ultrasound-assisted emulsifcation liquid phase microextraction were used in this method. The liver samples were digested by using DES-based digestion method. After digestion step, Cu(II) ions in aqueous phase were complexed with sodium dimethyl dithiocarbamate (NaDMDTC) and the obtained hydrophobic complex was extracted to tetrabuthylamonium chloride-decanoic acid DES phase. A microsample injection system coupled with fame atomic absorption spectrometer (MS-FAAS) was used in the detection of copper. LOD, LOQ, PF and % RSD were determined as 4.00, 13.2 µg L − 1 , 10 and 3.2%, respectively. The proposed microextraction procedure was successfully applied to copper contents of the liver samples. Keywords Deep eutectic solvents · Digestion · Ultrasound-assisted emulsifcation liquid phase microextraction · Copper · Liver · Flame atomic absorption spectrometer Introduction Heavy metals exposed by natural as well as anthropogenic including agriculture, industries, factories, mining and pro- cessing of metals that worse the quality and safety of food consumed by human [1–8]. The contaminated foods, such as fsh and meat, when exposed to polluted water, vegeta- ble and fruits are another important source of deposition of toxic elements in human organs and become dangerous. Trace elements play very important negative or positive roles in metabolism of humans. Due to these points, their accurate and precise determinations of trace elements in the environmental samples are one of the main interests of the analytical and environmental scientists [9–14]. The devel- opment of green analytical methods is a vital issue for ana- lytical chemists and importantly related with the use of new solvents, which can take the place of toxic organic solvents [15, 16]. The use of green solvents in diferent analytical applications minimizes or eliminates the environmental and health problems, which born of traditional toxic solvents as well as to decrease the process cost and evolve safety [17, 18]. The following guidelines for the fabrication of green sol- vents were proposed [15–18]: (1) replacement of dangerous solvents with environmentally friendly and safety solvents, (2) use of renewable resources to produce “bio-solvents”, (3) replacement of organic solvents with eco-friendly supercriti- cal fuids, or use of ionic liquids (ILs) that have low vapor pressure. In the last decade, ionic liquids, which consist of a cation and an anion functional group with more than 100 combinations, emerged and used for many analytical appli- cation as a new generation of solvents due to their excep- tional chemical and physical features [19–21]. While the “green” features of ILs have been announced [19–21], some reports have stressed that most of ILs have * Mustafa Soylak soylak@erciyes.edu.tr 1 Department of Chemistry, Faculty of Sciences, Van Yuzuncu Yil University, 65080 Van, Turkey 2 Department of Analytical Chemistry, Faculty of Pharmacy, Erciyes University, 38039 Kayseri, Turkey 3 Nanotechnology Research Center (ERNAM), Erciyes University, 38039 Kayseri, Turkey 4 Department of Chemistry, Faculty of Sciences, Erciyes University, 38039 Kayseri, Turkey