Utilization of montmorillonite nanocomposite incorporated with natural biopolymers and benzyl functionalized dicationic imidazolium based ionic liquid coated fiber for solid-phase microextraction of organochlorine pesticides prior to GC/MS and GC/ECD.

A novel montmorillonite clay (MMT) bionanocomposite modified with chitosan (CH), carboxymethyl cellulose (CMC), and benzylimidazolium based dicationic ionic liquid with tetraethylene glycol linker (DIL) was fabricated on stainless steel wire by in situ process. The MMT-CH-CMC-DIL coated solid-phase microextraction (SPME) fiber was examined for the determination of organochlorine pesticides (OCPs) in real samples by HS-SPME-GC method using mass spectrometry (MS) and electron capture detector (ECD). Under optimized conditions, the proposed method exhibited low limits of detection (0.

Chitosan and dicationic ionic liquid intercalated clay-coated solid-phase microextraction fiber for determination of sixteen polycyclic aromatic hydrocarbons in coffee and tea samples.

In the present study, solid-phase microextraction (SPME) fiber was prepared by coating clay (MMT)-chitosan (CH) and dicationic ionic liquid (DIL) onto the stainless-steel wire step by step. The characterization of fibers was performed by Fourier transform infrared spectroscopy, thermal analysis, x-ray diffraction analysis, and scanning electron microscopy. The prepared fibers were evaluated for separation and determination of 16 polycyclic aromatic hydrocarbons (PAHs) in coffee and tea samples in headspace- and direct immersion-SPME by coupling with gas chromatography/mass spectrometry.

Fabrication of montmorillonite/ionic liquid composite coated solid-phase microextraction fibers for determination of phenolic compounds in fruit juices by gas chromatography and liquid chromatography.

Novel montmorillonite composites including ionic liquid were prepared and utilized as coating materials for solid phase microextraction fibers. Ionic liquids containing amino terminated imidazolium cations with methyl and benzyl groups and hydrophobic anions (bis(trifluoromethylsulfonyl)imide) and hydrophilic anions (bromide and tetrafluoroborate) were intercalated to KSF-montmorillonite using stainless steel wire as support by using the layer-by-layer technique. After optimization of experimental conditions, solid phase microextraction (SPME) coupled to gas chromatography/mass spectrometry (SPME-GC/MS) after derivatization by silylation and high performance liquid chromatography/diode array detector (SPME-HPLC/DAD) were developed for the determination of 16 phenolic compounds.

Selective Preconcentration of Gold from Ore Samples.

A simple and selective method has been developed for preconcentration of gold in ore samples. The method is based on use of N, N-diethyl-N'-benzoylthiourea (DEBT) as selective chelating agent and Amberlite XAD-16 as solid sorbent. Sorption behavior of gold with DEBT impregnated resin under optimized conditions has been studied in batch process.

Determination of volatile polycyclic aromatic hydrocarbons in waters using headspace solid-phase microextraction with a benzyl-functionalized crosslinked polymeric ionic liquid coating.

A benzyl-functionalized crosslinked polymeric ionic liquid (PIL), produced through the co-polymerization of the 1-vinylbenzyl-3-hexadecylimidazolium bis[(trifluoromethyl)sulfonyl]imide (VBHDIM-NTf) ionic liquid (IL) monomer and 1,12-di(3-vinylbenzylimidazolium)dodecane bis[(trifluoromethyl)sulfonyl]imide ((DVBIM)C2NTf) IL crosslinker, was successfully used as a sorbent coating in headspace solid-phase microextraction (SPME) coupled to gas chromatography (GC) with flame-ionization detection (FID) to determine seven volatile polycyclic aromatic hydrocarbons (PAHs) in environmental water samples. Optimum extraction conditions for the PAHs when using the novel sorbent include an extraction temperature of 50°C, an ionic strength content adjusted with 30% (w/v) NaCl in the aqueous sample, and an extraction time of 60 min. The extraction performance of the crosslinked PIL fiber was compared to the SPME commercial coating polydimethylsiloxane fiber.

Zearalenone removal in synthetic media and aqueous part of canned corn by montmorillonite K10 and pillared montmorillonite K10.

The capacities of montmorillonite K10 (K10), aluminum pillared K10 (Al-K10), and iron pillared K10 (Fe-K10) to eliminate zearalenone (ZEN) from synthetic media and the aqueous part of canned corn were studied. Original clay and pillared clays were characterized in terms of X-ray powder diffraction analysis and N(2) adsorption-desorption isotherms. The maximum amounts of adsorption of ZEN by K10, Al-K10, and Fe-K10 at 25°C and pH 7 were 0.

Thin-layer chromatographic mobility of aryl-substituted porphyrins and their metalloporphyrins.

The migration behavior of aryl-substituted porphyrins and their metalloporphyrins with Zn(II), Ni(II), and Cu(II) were studied in high-performance thin-layer chromatography systems with silica gel and RP(18) plates using different organic mobile phases having different polarities. The (bromohydroxy)phenyl, (phenoxy)phenyl, and oxy(acetic acid)phenyl porphyrins migrated at similar rate. Chloromethylphenylporphyrin was weakly adsorbed on silica gel using either polar or nonpolar mobile phases.

Absorption and fluorescence properties of aryl substituted porphyrins in different media.

Absorption and fluorescence properties of aryl substituted porphyrins, 5,10,15,20-tetra-4-oxy(aceticacid)phenylporphyrin (TAPP), 5,10,15,20-tetra-(4-phenoxyphenyl) porphyrin (TPPP), 5,10,15,20-tetra-(3-bromo-4-hydroxyphenyl) porphyrin (TBHPP), and 5,10,15,20-tetra-p-chloromethylphenyl porphyrin (CMPP) were investigated. The UV/vis absorption, fluorescence and excited spectra as the fluorescence quantum yields and fluorescence lifetimes for the compounds were measured in organic solvents (chloroform (CHCl(3)), tetrahydrofuran (THF)) and immobilized media (PVC film, sol-gel matrix). The fluorescence quantum yields of TAPP and TPPP were higher than the others.

Solid phase extraction of gold(III) on silica gel modified with benzoylthiourea prior to its determination by flame atomic absorption spectrometry.

A new method has been developed for the determination of gold based on separation and preconcentration using silica gel modified with benzoylthiourea. The optimum experimental parameters for preconcentration of gold, such as acid concentration, sample flow rate, eluent and matrix ions, have been investigated. Gold could be quantitatively retained in the 0.

Solid phase extractive preconcentration of silver from aqueous samples.

N,N-dibutyl-N1-benzoylthiourea (DBBT) impregnated onto a polymeric matrix, Amberlite XAD-16 was prepared. The separation and enrichment of Ag(I) from solution was investigated. Effective extraction conditions were optimized in column methods prior to determination by atomic absorption spectrometry.

Reduction of ochratoxin a levels in red wine by bentonite, modified bentonites, and chitosan.

Adsorption method may play an important role to remove ochratoxin A (OTA) from wine by bentonite (B), nonylammonium bentonite (NB), dodecylammonium bentonite (DB), KSF-montmorillonite (KSF), and chitosan bead (CB). The optimum conditions of OTA adsorption from synthetic solutions were revealed at room temperature and pH 3.5.

Use of o-phenylene dioxydiacetic acid impregnated in Amberlite XAD resin for separation and preconcentration of uranium(VI) and thorium(IV).

The impregnation of o-phenylene dioxydiacetic acid (OPDA) into a polymeric matrix, Amberlite XAD-2000, is reported and was characterized by infrared spectroscopy. The amount of attached OPDA to the polymer resin was found to be 1.77mmolg(-1) resin.

Solid phase extractive preconcentration of trace metals using p-tert-butylcalix[4]arene-1,2-crown-4-anchored chloromethylated polymeric resin beads.

5,11,17,23-Tetrakis(1,1-dimethylethyl)-25,26-dihydroxy-27,28-crown-4-calix[4]arene in the cone conformation was synthesized. This p-tert-butylcalix[4]arene-1,2-crown-4 compound was then anchored with Merrifield chloromethylated resin beads. The modified polymeric resin was characterized by (1)H NMR, FT-IR and elemental analysis and used successfully for the separation and preconcentration of Cu(II), Cd(II), Co(II), Ni(II) and Zn(II) prior to their determination by FAAS.

Application of iron-rich natural clays in Camlica, Turkey for boron sorption from water and its determination by fluorimetric-azomethine-H method.

In this study, iron-rich natural Camlica Bentonites, CB1 and CB2, were used for the sorption of boron in water samples. Boron was determined by newly progressed fluorimetric azomethine-H method. The optimum conditions found using factorial designs are pH 10, 45 degrees C, 0.

Comparison of microwave digestion procedures for the determination of some elements in asphaltite ash using ICP-AES.

A microwave digestion procedure for asphaltite ash was developed in an attempt to facilitate routine analysis and obtain reproducible conditions or comparable results. The conditions of the most effective procedure for 0.1 g asphaltite ash samples are 1 ml of HNO3 + 3 ml of HCl + 1 ml of HF + 1 ml of deionized water as acid mixture and 15 min for digestion time.

Levels of trace and major elements in illicit heroin.

Ten elements, aluminum (Al), barium (Ba), calcium (Ca), cadmium (Cd), copper (Cu), iron (Fe), magnesium (Mg), manganese (Mn), lead (Pb), and zinc (Zn) were analyzed in 44 illicit heroin samples from Southeast Anatolia, Turkey. Illicit heroin samples were dissolved in nitric acid using microwave oven and were quantified by electrothermal atomic absorption spectrometry (Cd and Pb) and inductively coupled plasma-atomic emission spectrometry (Al, Ba, Ca, Cu, Fe, Mg, Mn, and Zn). The most abundant element was calcium, 4050 to 14,200 microg/g, which could be ascribed to the use of lime in the manufacturing process and/or as diluting agent.