Separation of inorganic anions on reversed-phase C18 columns with a phosphomolybdate mobile phase.

Reversed-phase high performance liquid chromatography (RP-HPLC) is the most widely used chromatographic method. In addition to hydrophobic interactions, additional interactions such as electrostatic interactions may participate in the retention behaviour of an analyte. This makes it possible to use RP-HPLC for many types of analyte.

The determination of zinc using flow injection and continuous flow analysis combined with a polymer inclusion film-coated column: Application to the determination of zinc in alloys and commercial lithium chloride.

A column coated with a polymer inclusion film (PIF) containing Aliquat 336 as carrier cast on glass beads packed in a glass tube is described for the separation, preconcentration, and determination of zinc(II) in flow injection analysis (FIA) and continuous flow analysis (CFA) systems. In the FIA method, 200 μL of a sample solution containing 2 mol/L lithium chloride is injected into a 2 mol/L lithium chloride stream. This converts zinc(II) ion into its anionic chlorocomplexes which are then extracted into the Aliquat 336-based PIF by anion exchange.

Automated rapid solid-phase extraction system for separation and preconcentration of trace elements using carboxymethylated polyethyleneimine-type chelating resin.

An automated system for the rapid separation and preconcentration of trace elements was developed. Carboxymethylated polyethyleneimine 600 (CM-PEI600), which is a partially carboxymethylated polyethyleneimine with a molecular weight of 600 Da, was used as a chelating resin to quantitatively recover trace elements under high-flow-rate conditions. For accurately and precisely determining trace elements, even with a rough control of the sample and eluent flow volumes, an internal standardization technique was employed for the solid-phase extraction and separation.

Applicability of Internal Standardization with Yttrium to the Solid-phase Extraction of Trace Elements in Groundwater and Wastewater Using an Aminocarboxylic Acid-type Chelating Resin.

Internal standardization was applied to the solid-phase extraction of trace elements using the following commercially available aminocarboxylic acid-type chelating resins: InertSep ME-2, NOBIAS Chelate PA-1, and Presep PolyChelate. The concentration of the trace elements in initial sample solution can be calculated by using the ratio of the added amount of the internal standard element, Y, in the initial sample solution to that in the final solution after the solid-phase extraction, which is proportional to the volume of the sample solution passed through the cartridge, and the ratio of the volume of the initial sample solution to that of a blank solution for preparing the calibration curve. In this solid-phase extraction, strict control of the volumes of the sample solution passed through the cartridge and the final solution after the solid-phase extraction is not needed because these are not used in the calculation of the trace element concentration.

Size resolved characteristics of urban and suburban bacterial bioaerosols in Japan as assessed by 16S rRNA amplicon sequencing.

To study the size-resolved characteristics of airborne bacterial community composition, diversity, and abundance, outdoor aerosol samples were analysed by 16S rRNA gene-targeted quantitative PCR and amplicon sequencing with Illumina MiSeq. The samples were collected using size-resolved samplers between August and October 2016, at a suburban site in Toyama City and an urban site in Yokohama City, Japan. The bacterial communities were found to be dominated by Actinobacteria, Firmicutes, and Proteobacteria.

Potential of Carboxymethylated Polyallylamine as a Functional Group on Chelating Resin for Solid-Phase Extraction of Trace Elements.

New chelating resins immobilizing carboxymethylated polyallylamine (CM-PAA) were prepared by immobilizing PAAs with some molecular weights on methacrylate resins and then carboxymethylating a part of amino groups in the PAAs using various amounts of sodium monochloroacetate. The molecular weight of PAA barely affected both the amount of PAA immobilized on the resin and the relationship between the carboxymethylation (CM) rate and the ratio of the amount of monochloroacetate used in the CM step. The selectivity of CM-PAA resin for solid-phase extraction of trace elements was almost the same as that of a resin immobilizing carboxylymethylated polyethyleneimine; 10 elements, namely Cd, Co, Cu, Fe, Mo, Ni, Pb, Ti, V, and Zn, could be quantitatively recovered over a wide pH range and alkali and alkaline earth elements were scarcely extracted under acidic and neutral conditions.

Thermal Decomposition Behavior of a Chelating Resin Immobilizing Carboxymethylated Polyethyleneimine: Possibility of Estimation of Carboxymethylation Rate.

Chelating resins immobilizing carboxymethylated polyethyleneimine (CM-PEI) with different carboxymethylation rates were prepared. The thermal decomposition behavior of CM-PEI resins was investigated using thermogravimetry-differential thermal analysis/photo ionization-quadrupole mass spectrometry (TG-DTA/PI-QMS) and ion attachment ionization-quadrupole mass spectrometry equipped with direct inlet probe (DIP/IA-QMS). The obtained results suggested that the carboxymethyl group decomposed at relatively low temperature (150 °C - 300 °C); the peak areas at m/z 45 and 59 in TG-DTA/PI-QMS and m/z 58, 70, and 72 in DIP/IA-QMS significantly increased with increasing carboxymethylation rate.

Phosphomethylated Polyethyleneimine-immobilized Chelating Resin: Role of Phosphomethylation Rate on Solid-Phase Extraction of Trace Elements.

Chelating resins immobilizing phosphomethylated polyethyleneimine (PM-PEI) with different phosphomethylation (PM) rates were prepared by using different amounts of both phosphonic acid and paraformaldehyde in the phosphomethylation of PEI immobilized on a methacrylate resin as a base resin. The extraction of many elements improved with increasing PM rate; REEs, Be, Fe, Mo, Ti, and V were quantitatively extracted at pH 2. The elution of the elements tended to become difficult with increasing PM rate.

A porous sintered material consisting of Presep PolyChelate as a chelating resin and particulate polyethylene as a thermoplastic binder for solid-phase extraction of trace elements.

Cylinder-type and disk-type sintered materials consisting of Presep PolyChelate, which is a commercially available chelating resin immobilizing carboxymethylated polyethyleneimine as a functional group, and particulate polyethylene as a thermoplastic binder were prepared using a polymer sintering technique. The sintered materials had a continuously porous structure. The sintering process at 130 °C for 20 min did not affect the ability of the chelating resin in the sintered materials; the selectivity of the sintered material was almost the same as that of the particulate chelating resin which was not sintered.

Improvement of Chromium(VI) Extraction from Acidic Solutions Using a Poly(vinyl chloride)-based Polymer Inclusion Membrane with Aliquat 336 as the Carrier.

An important reason for the inefficient extraction of Cr(VI) from its acidic solutions into polymer inclusion membranes (PIMs), consisting of poly(vinyl chloride) as the base-polymer and Aliquat 336 as the carrier, was found to be associated with the leaching of Aliquat 336 from the PIMs into the solutions, where it subsequently reduced the anionic Cr(VI) species to cationic Cr(III) species. The PIM extraction efficiency for Cr(VI) was significantly improved by the addition of NaNO to the solutions, which suppressed the leaching of Aliquat 336 and the reduction of Cr(VI) to Cr(III).

Diffusion-Controlled Recrystallization of Water Sorbed into Poly(meth)acrylates Revealed by Variable-Temperature Mid-Infrared Spectroscopy and Molecular Dynamics Simulation.

Recrystallization behaviors of water sorbed into four poly(meth)acrylates, poly(2-methoxyethyl acrylate), poly(tetrahydrofurfuryl acrylate), poly(methyl acrylate), and poly(methyl methacrylate), are investigated by variable-temperature mid-infrared (VT-MIR) spectroscopy and molecular dynamics (MD) simulation. VT-MIR spectra demonstrate that recrystallization temperatures of water sorbed into the polymers are positively correlated with their glass-transition temperatures reported previously. The present MD simulation shows that a lower-limit temperature of the diffusion for the sorbed water and the glass-transition temperatures of the polymers also have a positive correlation, indicating that the recrystallization is controlled by diffusion mechanism rather than reorientation mechanism.

Chelating resin immobilizing carboxymethylated polyethyleneimine for selective solid-phase extraction of trace elements: Effect of the molecular weight of polyethyleneimine and its carboxymethylation rate.

The effect of the molecular weight of polyethyleneimine (PEI), defined as a compound having two or more ethyleneamine units, and of its carboxymethylation rate (CM/N), represented by the ratio of ion-exchange capacity to the amount of N on the resin, on the selective solid-phase extraction ability of the chelating resin immobilizing carboxymethylated (CM) PEI was investigated. The chelating resins (24 types) were prepared by immobilization of diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, PEI300 (MW=ca. 300), and PEI600 (MW=ca.

Mid-infrared spectroscopic investigation of the perfect vitrification of poly(ethylene glycol) aqueous solutions.

Crystallization/recrystallization behaviors of poly(ethylene glycol) (PEG) aqueous solutions with water contents (WC's) of ∼36-51 wt % were investigated by temperature-variable mid-infrared spectroscopy. At a WC of 43.2 wt %, crystallization and recrystallization of water and PEG were not observed.

The use of a polymer inclusion membrane as a sorbent for online preconcentration in the flow injection determination of thiocyanate impurity in ammonium sulfate fertilizer.

A polymer inclusion membrane (PIM) is used for the first time as a sorbent in the construction of a preconcentration column to enhance the sensitivity in flow injection analysis (FIA). The PIM-coated column is readily prepared by coating the PIM containing poly(vinyl chloride), Aliquat 336, and 1-tetradecanol onto glass beads packed in a glass tube. The determination of trace amounts of thiocyanate in ammonium sulfate fertilizer demonstrates the potential of the proposed PIM-coated column in FIA.

Chelating materials immobilizing carboxymethylated pentaethylenehexamine and polyethyleneimine as ligands.

This article presents an overview of our recent progress on the development of chelating materials. Carboxymethylated pentaethylenehexamine (CM-PEHA) and polyethyleneimine (CM-PEI) as chelating ligands show excellent performance for the solid-phase extraction of trace elements. Chelating resins immobilizing these ligands can be readily prepared by immobilizing PEHA and PEI on methacrylate resins and then carboxymethylating them.

Potential of Presep(®) PolyChelate as a chelating resin: comparative study with some aminocarboxylic acid-type resins.

The potential of Presep(®) PolyChelate as a chelating resin was studied in detail. The chelating resin with extraction capacity for Cu of 0.30 mmol L(-1) could quantitatively extract Cd, Co, Cu, Fe, Mo, Ni, Pb, V, and Zn at pH 4 or 5.

Molecular properties and extracellular processing of the lipase of Staphylococcus warneri M.

Staphylococcus warneri M exhibited extracellular lipase activity. By zymogram analysis of extracellular proteins, multiple bands were detected and the profiles changed depending on the bacterial growth phase. N-terminal amino acid sequences of three bands (N1-N3) were determined.

Chelating fibers prepared with a wet spinning technique using a mixture of a viscose solution and a polymer ligand for the separation of metal ions in an aqueous solution.

Chelating fibers containing polymer ligands such as carboxymethylated polyallylamine, carboxymethylated polyethyleneimine, and a copolymer of diallylamine hydrochloride/maleic acid were prepared with a wet spinning technique using mixtures of a viscose solution and the polymer ligands. The chelating fibers obtained effectively adsorbed various metal ions, including Cd(II), Co(II), Cr(III), Cu(II), Fe(III), Mn(II), Ni(II), Pb(II), Ti(IV), and Zn(II). The metal ions adsorbed could be readily desorbed using 0.

Solid-phase extraction of cobalt(II) from lithium chloride solutions using a poly(vinyl chloride)-based polymer inclusion membrane with Aliquat 336 as the carrier.

The extraction of cobalt(II) from solutions containing various concentrations of lithium chloride, hydrochloric acid, and mixtures of lithium chloride plus hydrochloric acid is reported using a poly(vinyl chloride) (PVC)-based polymer inclusion membrane (PIM) containing 40% (w/w) Aliquat 336 as a carrier. The extraction from lithium chloride solutions and mixtures with hydrochloric acid is shown to be more effective than extraction from hydrochloric acid solutions alone. The solution concentrations giving the highest amounts of extraction are 7 mol L(-1) for lithium chloride and 8 mol L(-1) lithium chloride plus 1 mol L(-1) hydrochloric acid for mixed solutions.

Determination of cadmium in water samples by liquid electrode plasma atomic emission spectrometry after solid phase extraction using a mini cartridge packed with chelate resin immobilizing carboxymethylated pentaethylenehexamine.

Solid phase extraction using a mini cartridge packed with 22 mg of chelate resin immobilizing carboxymethylated pentaethylenehexamine was successfully utilized for separation/preconcentration of cadmium in water samples prior to liquid electrode plasma atomic emission spectrometric (LEP-AES) determination. The combined method with the extraction and LEP-AES was applicable to the determination of cadmium in the certified reference materials (EU-L-1 wastewater and ES-L-1 groundwater); the detection limit was 0.20 microg in 200 mL of sample solution (500-fold preconcentration).

A sensitive and selective method for determination of gold(III) based on electrothermal atomic absorption spectrometry in combination with dispersive liquid-liquid microextraction using dicyclohexylamine.

A combined method with dispersive liquid-liquid microextraction (DLLME) and electrothermal atomic absorption spectrometry (ETAAS) has been developed for determining gold(III). Dicyclohexylamine, a new extractant for gold(III), showed excellent performance in DLLME. Acetone was indispensable to the quantitative extraction of gold(III), contributing to decrease in hydration, decrease in the difference in the dielectric constants between the supernatant phase and the sedimented phase, and dissolution of a part of chloroform as an extraction solvent to the supernatant phase as well as improvement of dipersibility.

Selective removal of mercury(II) from wastewater using polythioamides.

The potential and feasibility of polythioamides as Hg(II) sorbents were evaluated. Powdered polythioamides quantitatively sorbed Hg(II) from an aqueous solution at pH 1-8. The sorption of Hg(II) on polythioamides obeyed the Langmuir adsorption isotherm; the sorption capacity was 0.

Continuous flow photocatalytic treatment integrated with separation of titanium dioxide on the removal of phenol in tap water.

We studied the continuous flow photocatalytic treatment integrated with separation/reuse of titanium dioxide on the removal of phenol (20 mg l(-1)) in electrolytes containing tap water. A circulative flow tubular photoreactor and a separation tank were used, where inflow of phenol continuously flowed into a mixing tank (for titanium dioxide suspension) and treated water overflowed from the separation tank. Black light and sunlight were used by turns as the light source on the photocatalytic treatment.

Inductively coupled plasma atomic emission spectrometric determination of 27 trace elements in table salts after coprecipitation with indium phosphate.

The coprecipitation method using indium phosphate as a new coprecipitant has been developed for the separation of trace elements in table salts prior to their determination using inductively coupled plasma atomic emission spectrometry (ICP-AES). Indium phosphate could quantitatively coprecipitate 27 trace elements, namely, Be, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, Pb, Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu, in a table salt solution at pH 10. The rapid coprecipitation technique, in which complete recovery of the precipitate was not required in the precipitate-separation process, was completely applicable, and, therefore, the operation for the coprecipitation was quite simple.

A solid phase extraction using a chelate resin immobilizing carboxymethylated pentaethylenehexamine for separation and preconcentration of trace elements in water samples.

A chelate resin immobilizing carboxymethylated pentaethylenehexamine (CM-PEHA resin) was prepared, and the potential for the separation and preconcentration of trace elements in water samples was evaluated through the adsorption/elution test for 62 elements. The CM-PEHA resin could quantitatively recover various elements, including Ag, Cd, Co, Cu, Fe, Ni, Pb, Ti, U, and Zn, and rare earth elements over a wide pH range, and also Mn at pH above 5 and V and Mo at pH below 7. This resin could also effectively remove major elements, such as alkali and alkaline earth elements, under acidic and neutral conditions.