This work presents ultrasound-assisted dispersive micro solid phase extraction (USA DMSPE) for preconcentration of fluorine (F) in water and herb samples. TiO2 nanoparticles (NPs) were used as an adsorbent. The determination with slurry sampling was performed via molecular absorption of calcium monofluoride (CaF) at 606.440 nm using a high-resolution continuum source electrothermal absorption s...

A time-based sequential dispensing on-line column preconcentration procedure for mercury determination at trace levels by cold vapour generation inductively coupled plasma atomic emission spectrometry (CV-ICP-AES), by means of a unified module of a preconcentration column and a gas-liquid separator (PCGLS) is described. The complex of mercury formed on-line with ammonium pyrrolidine dithiocarba...

Micellar electrokinetic chromatography (MEKC) using a cationic surfactant as a pseudostationary phase was examined to separate anionic metal cyclohexane-1,2-diaminetetraacetic acid (CDTA) complexes. Cetyltrimethylammonium chloride (CTAC) was employed as the cationic surfactant micelle, its addition leading to EOF reversal. Cu(II), Co(II), Zn(II), Mn(II) and Pb(II) were used as test analytes, an...

This paper describes an integrated flow injection (FI) system for the determination of ammonia, sulphate and Fe(II)/Fe(III) which can work unattended for long periods. The system was designed for the determination of individual analytes in long series of samples. Each batch of samples requires manual selection of parameters and units, such as wavelength for monitoring, preconcentration column, ...

The applicability of poly(acrylamide) grafted onto cross-linked poly(4-vinyl pyridine) (P4-VP-g-PAm) has been investigated for the separation, preconcentration and speciation of Hg(II) and MeHg(I). In batch experiments, Hg(II) was quantitatively retained (≥95%) in the pH range of 1.0-8.0, whereas the sorption of MeHg(I) was insignificant in the pH range of 1.0-2.0. Freundlich and Langmuir isoth...

A rapid, selective and sensitive method for the preconcentration and determination of uranium (VI) by cloud point extraction (CPE) was developed. The method was based on the color reaction of 5.00 ng mL uranium (VI) with 1.5×10 mol L of chromotrope 2R in the presence of 0.015 mol L potassium iodide at pH 8 in HEPES buffer and mixed micelle-mediated extraction of complex. The mixture of a nonion...

This paper reports the development of a new methodology for the determination of cobalt in biological samples by using a flow injection system with loaded DPTH-gel as solid phase to preconcentrate analytes. The procedure is based on the on-line preconcentration of cobalt on a microcolumn of 1,5-bis(di-2-pyridyl)methylene thiocarbohydrazide immobilized on silica gel (DPTH-gel). The trapped cobal...

A simple and convenient method based on cloud point extraction was proposed for the determination of copper. The extraction was carried out in the presence of 2-[(2-mercaptophenylimino)methyl]phenol (MPMP) as the chelating ligand and octylphenoxypolyethoxyethanol (Triton X-114) as the non-ionic surfactant. After phase separation, the surfactant rich phase containing the complex was diluted with...