A green and fast sample preparation method based on reversed-phase dispersive liquid–liquid microextraction was developed for the separation preconcentration of several elements in gasoline samples before ICP-OES determination.

Analysis of low-abundance components in small samples remains a challenge within bioanalytical chemistry, and new techniques for sample pretreatments followed by sensitive and informative detection are required. In this thesis, procedures for preconcentration and separation of proteins and peptides in open microchannels fabricated on silicon microchips are presented. Analyte electromigration wa...

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...

This paper presents a bipolar electrode (BPE) device in a microfluidic dual-channel design for concurrent preconcentration and separation of composite DNA containing samples. The novelty of the present effort relies on the combination of BPE-induced ion concentration polarization (ICP) and end-labeled free-solution electrophoresis (ELFSE). The ion concentration polarization effect arising from ...

A fluidic microchip incorporating a convergent microchannel and a Nafion-nanoporous membrane is proposed for the preconcentration and separation of multi-species samples on a single platform. In the device, sample preconcentration is achieved by means of the ion concentration polarization effect induced at the micro/nano interface under the application of an external electric field, while speci...

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 novel, simple, sensitive and effective method has been developed for preconcentration of Hg(II) on nano-Fe3O4-DOP-ED solid-phase extraction adsorbent. In this paper, Dioctyl phthalate (DOP) was used to encapsulate nano-Fe3O4 and produce a nano-Fe3O4-DOP sorbent based new sorbent was prepared. This was treated with ethylenediamine (ED) in another solvent-free procedure for the formation of a n...

: a new fibrous adsorbent was prepared by grafting acrylic acid /acryl amide (aa/aam) co-monomers onto poly(ethylene terephtalat) (pet) fibers. the resulting sorbent has been characterized by fourier transform infrared spectroscopy (ft-ir), thermo gravimetric analysis (tga), scanning electron microscopy (sem) and elemental analysis and studied for the preconcentration and determination of trace...

a simple and sensitive method has been developed for the preconcentration and determination of trace level of co(ii) using uv-vis spectrophotometry. β-cyclodextrin polymer modified with 1-(2-pyridylazo)-2-naphthol (pan) is used for the preconcentration of co(ii) from samples at ph 8.5. the polymer is synthesized and characterized using elemental analysis, ft-ir and sem analysis. the factors aff...

The anodic stripping voltammetry at a carbon paste electrode modified with thiol terminated self-assembled monolayer on mesoporous silica (SH-SAMMS) provides a new sensor for simultaneous detection of lead (Pb2+) and mercury (Hg2+) in aqueous solutions. The overall analysis involved a two-step procedure: an accumulation step at open circuit, followed by medium exchange to a pure electrolyte sol...