Dispersive liquid liquid microextraction combined with electrothermal vaporization inductively coupled plasma mass spectrometry for the speciation of inorganic selenium in environmental water samples.

A novel method based on dispersive liquid liquid microextraction (DLLME) followed by electrothermal vaporization inductively coupled plasma mass spectrometry (ETV-ICP-MS) determination was proposed for the speciation of inorganic selenium by using 5-mercapto-3-phenyl-1,3,4-thiadiazole-2-thione potassium salt (Bismuthiol II) as both chelating reagent and chemical modifier. In this method, 500 μL ethanol (as disperser solvent) containing 70 μL chloroform (as extraction solvent) and 0.2 g L(-1) Bismuthiol II (as chelating reagent) was rapidly injected into a sample solution to form cloudy solution.

Chiral speciation and determination of selenomethionine enantiomers in selenized yeast by ligand-exchange micellar electrokinetic capillary chromatography after solid phase extraction.

A new phenylalanine derivative (L-N-(2-hydroxy-propyl)-phenylalanine, L-HP-Phe) was synthesized and its chelate with Cu(II) (Cu(II)-(L-HP-Phe)(2)) was used as the chiral selector for the ligand-exchange (LE) chiral separation of D,L-selenomethionine (SeMet) in selenized yeast samples by micelle electrokinetic capillary chromatography (MEKC). In order to improve the sensitivity of MEKC-UV, two-step preconcentration strategy was employed, off-line solid phase extraction (SPE) and on-line large volume sample stacking (LVSS). D,L-SeMet was first retained on the Cu(II) loaded mesoporous TiO(2), then eluted by 0.

Speciation of selenomethionine and selenocystine using online micro-column containing Cu(II) loaded nanometer-sized Al2O3 coupled with ICP-MS detection.

A flow injection online speciation procedure by using micro-column packed with Cu(II) loaded nanometer-sized Al(2)O(3) coupled to inductively coupled plasma mass spectrometry (ICP-MS) for the separation and determination of selenomethionine (SeMet) and selenocystine (SeCys(2)) has been developed. The main factors affecting the separation and preconcentration of SeMet and SeCys(2) including pH value, sample flow rate, eluent concentration, eluent volume and flow rate, and interfering ions have been investigated. It was found that SeCys(2) could be selectively retained by micro-column packed with Cu(II) loaded nanometer-sized Al(2)O(3) at pH 4.

Separation and determination of seleno amino acids using gas chromatography hyphenated with inductively coupled plasma mass spectrometry after hollow fiber liquid phase microextraction.

A new derivatization-extraction method for preconcentration of seleno amino acids using hollow fiber liquid phase microextraction (HF-LPME) was developed for the separation and determination of seleno amino acids in biological samples by gas chromatography-inductively coupled plasma mass spectrometry (GC-ICP-MS). Derivatization was performed with ethyl chloroformate (ECF) to improve the volatility of seleno amino acids. Parameters influencing microextraction, including extraction solvent, pH of sample solution, extraction time, stirring speed, and inorganic salt concentration have been investigated.

Electrothermal vaporization inductively coupled plasma atomic emission spectrometry determination of gold, palladium, and platinum using chelating resin YPA(4) as both extractant and chemical modifier.

A new method for determination of trace gold (Au), palladium (Pd), and platinum (Pt) in environmental and geological samples by electrothermal vaporization (ETV)-inductively coupled plasma atomic emission spectrometry (ICP-AES) with the use of chelating resin YPA(4) as both solid phase extractant and chemical modifier has been developed. The resin loaded with analytes was prepared to slurry and directly introduced into the graphite furnace without any pretreatment. The factors affecting the vaporization behaviors of Au, Pd, and Pt were investigated in detail.

High-sensitivity capillary electrophoresis for speciation of organomercury in biological samples using hollow fiber-based liquid-liquid-liquid microextraction combined with on-line preconcentration by large-volume sample stacking.

A hollow fiber-based liquid-liquid-liquid microextraction (HF-LLLME) combined with on-line large-volume sample stacking (LVSS) has been developed for the speciation of organomercury in biological samples by CE with UV detection. Separation was achieved in less than 11 min with an electrolyte consisting of 35 mM sodium tetraborate at pH 9.1.

Organic and inorganic selenium speciation in environmental and biological samples by nanometer-sized materials packed dual-column separation/preconcentration on-line coupled with ICP-MS.

A novel, fast, and cheap nonchromatographic method for direct speciation of dissolved inorganic and organic selenium species in environmental and biological samples was developed by flow injection (FI) dual-column preconcentration/separation on-line coupled with ICP-MS determination. In the developed technique, the first column packed with nanometer-sized Al(2)O(3) could selectively adsorb the inorganic selenium [Se(IV), Se(VI)], and the retained inorganic selenium could be eluted by 0.2 mol l(-1) NaOH, while the organic Se [selenocystine (SeCys(2)) and selenomethionine (Se-Met)] was not retained.

Analysis of PBDEs in soil, dust, spiked lake water, and human serum samples by hollow fiber-liquid phase microextraction combined with GC-ICP-MS.

A novel method for the analysis of four polybrominated diphenyl ethers (PBDEs) in environmental and human serum samples based on hollow fiber-liquid phase microextraction (HF-LPME) followed by gas chromatography-inductively coupled plasma mass spectrometric (GC-ICP-MS) detection has been developed. The organic solvent in the porous hollow fiber was first dipped into the sample for extraction at a given time, and the retracted organic phase was introduced into the GC-ICP-MS for analysis. The addition of methanol has a strong effect on the HF-LPME extraction efficiency.