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You searched for: Journal Journal of chromatography Remove constraint Journal: Journal of chromatography Publication Year 2011 Remove constraint Publication Year: 2011 Source 2011 v.1218 no.33 Remove constraint Source: 2011 v.1218 no.33
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1. A chromatographic study on the exceptional enantioselectivity of cellulose tris(4-methylbenzoate) towards C5-chiral 4,5-dihydro-(1H)-pyrazole derivatives

Author:
Cirilli, Roberto; Alcaro, Stefano; Fioravanti, Rossella; Ferretti, Rosella; Bolasco, Adriana; Gallinella, Bruno; Faggi, Cristina
Source:
Journal of chromatography 2011 v.1218 no.33 pp. 5653-5657
ISSN:
0021-9673
Subject:
cellulose; enantiomers; ethanol; high performance liquid chromatography; thermodynamics
Abstract:
... A set of ten C5-chiral 4,5-dihydro-(1H)-pyrazole derivatives was synthesized and analyzed by high-performance liquid chromatography (HPLC) on the polysaccharide-based Chiralcel OJ-H chiral stationary phase (CSP). The enantioseparations were carried out using pure ethanol as eluent. Different structural elements of the investigated compounds were recognized for obtaining a very high enantioselectiv ...
DOI:
10.1016/j.chroma.2011.06.081

2. Analysis of primary aromatic amines in the mainstream waterpipe smoke using liquid chromatography–electrospray ionization tandem mass spectrometry

Author:
Schubert, Jens; Kappenstein, Oliver; Luch, Andreas; Schulz, Thomas G.
Source:
Journal of chromatography 2011 v.1218 no.33 pp. 5628-5637
ISSN:
0021-9673
Subject:
aniline; chromatography; detection limit; glass fibers; ionization; particulates; smoke; tandem mass spectrometry
Abstract:
... In recent years waterpipe smoking has spread worldwide and emerged as global health issue. Yet only little is known on the composition of waterpipe smoke. Here, we present a study on the identification and quantification of primary aromatic amines (PAAs) in this complex environmental matrix. Smoking of the waterpipe was conducted with a smoking machine and particulate matter was collected on glass ...
DOI:
10.1016/j.chroma.2011.06.072

3. Are the results of customary methods for analyzing dioxin and dioxin-like compound congener profiles court-proof?

Author:
Uhlig, Steffen; Eichler, Stefanie
Source:
Journal of chromatography 2011 v.1218 no.33 pp. 5688-5693
ISSN:
0021-9673
Subject:
chromatography; cluster analysis; neural networks; principal component analysis; toxicity; uncertainty
Abstract:
... The congener profile of samples contaminated with dioxin and dioxin-like compounds allows identifying sources of contamination. This article studies the statistical methods of congener profile analysis reported in the literature with respect to the reliability of obtained results. The performance of customary analysis methods regarding raw data transformation and applied TEF (toxic equivalency fac ...
DOI:
10.1016/j.chroma.2011.06.080

4. Characterization of small interfering RNA by non-denaturing ion-pair reversed-phase liquid chromatography

Author:
Noll, Bernhard; Seiffert, Stephan; Vornlocher, Hans-Peter; Roehl, Ingo
Source:
Journal of chromatography 2011 v.1218 no.33 pp. 5609-5617
ISSN:
0021-9673
Subject:
annealing; gene expression; mass spectrometry; oligoribonucleotides; reversed-phase liquid chromatography; small interfering RNA
Abstract:
... Small interfering RNAs (siRNA) are emerging as a novel therapeutic modality for the specific inhibition of target gene expression. siRNA are typically formed by annealing of two complementary single stranded oligoribonucleotides. Compared to purity determination of non-hybridized single strands by denaturing chromatographic methods, characterization of the hybridized duplex is challenging. Here we ...
DOI:
10.1016/j.chroma.2011.06.057

5. Combined cation-exchange and extraction chromatographic method of pre-concentration and concomitant separation of Cu(II) with high molecular mass liquid cation exchanger after its online detection

Author:
Mandal, B.; Roy, U.S.; Datta, D.; Ghosh, N.
Source:
Journal of chromatography 2011 v.1218 no.33 pp. 5644-5652
ISSN:
0021-9673
Subject:
acetates; lead; industrial wastes; cadmium; sorption isotherms; alloys; molecular weight; metal ions; copper; models; cation exchange; paper chromatography; silica gel; temperature; bismuth; mercury; tin; entropy; pH; desorption
Abstract:
... A selective method has been developed for the extraction chromatographic trace level separation of Cu(II) with Versatic 10 (liquid cation exchanger) coated on silanised silica gel (SSG-V10). Cu(II) has been extracted from 0.1M acetate buffer at the range of pH 4.0–5.5. The effects of foreign ions, pH, flow-rate, stripping agents on extraction and elution have been investigated. Exchange capacity o ...
DOI:
10.1016/j.chroma.2011.06.083

6. Determination of aliphatic amines by gas chromatography–mass spectrometry after in-syringe derivatization with pentafluorobenzoyl chloride

Author:
Singh, Deepesh Kumar; Sanghi, Sunil Kumar; Gowri, Sorna; Chandra, Navin; Sanghi, Shail Bala
Source:
Journal of chromatography 2011 v.1218 no.33 pp. 5683-5687
ISSN:
0021-9673
Subject:
amines; bicarbonates; correlation; derivatization; detection limit; gas chromatography-mass spectrometry; industrial wastes; lakes; microextraction; mixing; molecular weight; pH; rivers; solvents; system optimization; temperature; wastewater
Abstract:
... A simple and highly sensitive gas chromatographic method has been developed for the determination of low molecular weight short-chain aliphatic amines (SCAAs) after their simultaneous extraction and in-syringe derivatization with pentafluorobenzoyl chloride (PFBOC). Derivatization of the low molecular weight aliphatic amines in bicarbonate buffer of pH 10.5 with PFBOC was followed by immersed solv ...
DOI:
10.1016/j.chroma.2011.06.022

7. Determination of organochlorine pesticide residues in fatty foods: A critical review on the analytical methods and their testing capabilities

Author:
Chung, Stephen W.C.; Chen, Benedict L.S.
Source:
Journal of chromatography 2011 v.1218 no.33 pp. 5555-5567
ISSN:
0021-9673
Subject:
animals; chlordecone; chromatography; endrin; foods; metabolites; monitoring; persistent organic pollutants; pesticide residues
Abstract:
... Organochlorine pesticide (OCP) residues in foods have been of concern for several decades. However, the analysis of some of the OCPs and their metabolites or derivatives, such as endrin aldehyde, endrin ketone, nonachlor, etc. in fatty foods (including foods of animal and plant origin), was not commonly included in routine monitoring programme. Recently, the Stockholm Convention introduced nine pl ...
DOI:
10.1016/j.chroma.2011.06.066

8. Development of a four-zone carousel process packed with metal ion-imprinted polymer for continuous separation of copper ions from manganese ions, cobalt ions, and the constituent metal ions of the buffer solution used as eluent

Author:
Jo, Se-Hee; Park, Chanhun; Yi, Sung Chul; Kim, Dukjoon; Mun, Sungyong
Source:
Journal of chromatography 2011 v.1218 no.33 pp. 5664-5674
ISSN:
0021-9673
Subject:
manganese; cobalt; copper; heavy metals; chromatography; adsorbents; polymers; metal ions; washing
Abstract:
... A three-zone carousel process, in which Cu(II)-imprinted polymer (Cu-MIP) and a buffer solution were employed as adsorbent and eluent respectively, has been developed previously for continuous separation of Cu²⁺ (product) from Mn²⁺ and Co²⁺ (impurities). Although this process was reported to be successful in the aforementioned separation task, the way of using a buffer solution as eluent made it i ...
DOI:
10.1016/j.chroma.2011.06.094

9. Direct aqueous determination of glyphosate and related compounds by liquid chromatography/tandem mass spectrometry using reversed-phase and weak anion-exchange mixed-mode column

Author:
Hao, Chunyan; Morse, David; Morra, Franca; Zhao, Xiaoming; Yang, Paul; Nunn, Brian
Source:
Journal of chromatography 2011 v.1218 no.33 pp. 5638-5643
ISSN:
0021-9673
Subject:
anion exchange; chemical structure; derivatization; detection limit; drinking water; glufosinate; glyphosate; groundwater; isotope dilution technique; liquid chromatography; metal ions; monitoring; storage time; surface water; tandem mass spectrometry; water solubility
Abstract:
... Analysis of the broad-spectrum herbicide glyphosate and its related compounds is quite challenging. Tedious and time-consuming derivatization is often required for these substances due to their high polarity, high water solubility, low volatility and molecular structure which lacks either a chromophore or fluorophore. A novel liquid chromatography/tandem mass spectrometry (LC/MS–MS) method has bee ...
DOI:
10.1016/j.chroma.2011.06.070

10. Enantioseparation of phenylsuccinic acid by high speed counter-current chromatography using hydroxypropyl-β-cyclodextrin as chiral selector

Author:
Tong, Shengqiang; Yan, Jizhong; Guan, Yi-Xin; Lu, Youming
Source:
Journal of chromatography 2011 v.1218 no.33 pp. 5602-5608
ISSN:
0021-9673
Subject:
countercurrent chromatography; equations; high performance liquid chromatography; pH; solvents; temperature; thermodynamics
Abstract:
... High speed counter-current chromatography (HSCCC) was successfully applied to resolution of phenylsuccinic acid (PSA) with hydroxypropyl-β-cyclodextrin (HP-β-CD) as chiral selector (CS). The two-phase solvent system composed of n-hexane–methyl tert-butyl ether–0.1molL⁻¹ phosphate buffer solution with pH=2.51 (0.5:1.5:2, v/v/v) was selected. Influence factors involved in the chiral separation were ...
DOI:
10.1016/j.chroma.2011.06.023

11. External calibration in Gas Chromatography–Combustion–Isotope Ratio Mass Spectrometry measurements of endogenous androgenic anabolic steroids in sports doping control

Author:
Kioussi, Maroula K.; Angelis, Yiannis S.; Cawley, Adam T.; Koupparis, Michalis; Kazlauskas, Rymantas; Brenna, J. Thomas; Georgakopoulos, Costas G.
Source:
Journal of chromatography 2011 v.1218 no.33 pp. 5675-5682
ISSN:
0021-9673
Subject:
anabolic steroids; androsterone; carbon dioxide; chromatography; equipment; least squares; mass spectrometry; metabolites; normal values; sports; urine; Australia; Greece; United States
Abstract:
... An alternative calibration procedure for the Gas Chromatography–Combustion–Isotope Ratio Mass Spectrometry (GC–C–IRMS) measurements of the World Antidoping Agency (WADA) Accredited Laboratories is presented. To alleviate the need for externally calibrated CO₂ gas for GC–C–IRMS analysis of urinary steroid metabolites, calibration using an external standard mixture solution of steroids with certifie ...
DOI:
10.1016/j.chroma.2011.06.014

12. Label-free electrical discrimination of cells at normal, apoptotic and necrotic status with a microfluidic device

Author:
Gou, Hong-Lei; Zhang, Xian-Bo; Bao, Ning; Xu, Jing-Juan; Xia, Xing-Hua; Chen, Hong-Yuan
Source:
Journal of chromatography 2011 v.1218 no.33 pp. 5725-5729
ISSN:
0021-9673
Subject:
electric field; gold; electrodes; chromatography; capacitance; flow cytometry; sorting; screening; apoptosis
Abstract:
... As a label-free alternative of conventional flow cytometry, chip-based impedance measurement for single cell analysis has attracted increasing attentions in recent years. In this paper, we designed a T-shape microchannel and fabricated a pair of gold electrodes located horizontally on each side of the microchannel using a transfer printing method. Instant electric signals of flowing-through single ...
DOI:
10.1016/j.chroma.2011.06.102

13. Low-parachor solvents extraction and thermostated micro-thin-layer chromatography separation for fast screening and classification of spirulina from pharmaceutical formulations and food samples

Author:
Zarzycki, Paweł K.; Zarzycka, Magdalena B.; Clifton, Vicki L.; Adamski, Jerzy; Głód, Bronisław K.
Source:
Journal of chromatography 2011 v.1218 no.33 pp. 5694-5704
ISSN:
0021-9673
Subject:
Spirulina; acetone; biodegradation; chemometrics; chemotaxonomy; chlorophyll; cluster analysis; drug formulations; dyes; equipment; foods; fractionation; herbs; high performance liquid chromatography; iodine; methanol; pigments; principal component analysis; quality control; screening; solvents; tetrahydrofuran
Abstract:
... The goal of this paper is to demonstrate the separation and detection capability of eco-friendly micro-TLC technique for the classification of spirulina and selected herbs from pharmaceutical and food products. Target compounds were extracted using relatively low-parachor liquids. A number of the spirulina samples which originated from pharmaceutical formulations and food products, were isolated u ...
DOI:
10.1016/j.chroma.2011.06.065

14. Multilinear gradient elution optimization in reversed-phase liquid chromatography based on logarithmic retention models: Application to separation of a set of purines, pyrimidines and nucleosides

Author:
Nikitas, P.; Pappa-Louisi, A.; Agrafiotou, P.; Mansour, A.
Source:
Journal of chromatography 2011 v.1218 no.33 pp. 5658-5663
ISSN:
0021-9673
Subject:
acetonitrile; algorithms; equations; models; nucleosides; purines; pyrimidines; reversed-phase liquid chromatography; solutes
Abstract:
... The analytical solutions of the fundamental equation of the multilinear gradient elution are derived in two cases, when the dependence of the logarithm of the solute retention (lnk) upon the volume fraction of organic modifier (φ) is a three-parameter logarithmic expression, and when a simple linear relationship between lnk and lnφ is adopted. The derived theoretical expressions for retention time ...
DOI:
10.1016/j.chroma.2011.06.084

15. Novel cyclodextrin chiral stationary phases for high performance liquid chromatography enantioseparation: Effect of cyclodextrin type

Author:
Lai, Xianghua; Tang, Weihua; Ng, Siu-Choon
Source:
Journal of chromatography 2011 v.1218 no.33 pp. 5597-5601
ISSN:
0021-9673
Subject:
alcohols; amines; gamma-cyclodextrin; high performance liquid chromatography; models; silica
Abstract:
... Three novel chiral stationary phases (CSPs) were prepared by regioselective chemical immobilization of mono(6ᴬ-N-allylamino-6ᴬ-deoxy)perphenylcarbamoylated (PICD) α-, β-, and γ-cyclodextrins (CDs) onto silica support via hydrosilylation. Their enantioseparation properties in high performance liquid chromatography (HPLC) were evaluated with a large spectrum of racemates including flavanone compound ...
DOI:
10.1016/j.chroma.2011.06.020

16. Potential of long chain ionic liquids for on-line sample concentration techniques: Application to micelle to solvent stacking

Author:
Quirino, Joselito P.; Anres, Philippe; Sirieix- Plénet, Juliette; Delaunay, Nathalie; Gareil, Pierre
Source:
Journal of chromatography 2011 v.1218 no.33 pp. 5718-5724
ISSN:
0021-9673
Subject:
capillary zone electrophoresis; cationic surfactants; chromatography; herbicides; hydrophobicity; ionic liquids; micelles; solubility
Abstract:
... The performance of micelle to solvent stacking (MSS) in capillary zone electrophoresis (CZE) was improved for anionic analytes using the long chain ionic liquid type cationic surfactant 1-dodecyl-3-methylimidazolium tetrafluoroborate (C₁₂-MIM-BF₄). The peak heights and corrected peak areas of the test profens and herbicides were enhanced up to 59 and 110-fold, respectively when compared to typical ...
DOI:
10.1016/j.chroma.2011.06.071

17. Preparation and characterization of amino functionalized nano-composite material and its application for multi-residue analysis of pesticides in cabbage by gas chromatography–triple quadrupole mass spectrometry

Author:
Zhao, Yong-Gang; Shen, Hao-Yu; Shi, Jia-Wei; Chen, Xiao-Hong; Jin, Mi-Cong
Source:
Journal of chromatography 2011 v.1218 no.33 pp. 5568-5580
ISSN:
0021-9673
Subject:
Fourier transform infrared spectroscopy; acetonitrile; adsorbents; cabbage; chromatography; detection limit; mass spectrometry; multiresidue analysis; organophosphorus pesticides; pigments; solid phase extraction; solvents; thermogravimetry; trans-chlordane; transmission electron microscopy
Abstract:
... In this paper, a novel and recyclable amino-functionalized nano-composite material (NCM) using tetraethylenepentamine (TEPA) as a coupling agent was synthesized. The properties of the TEPA-NCM were characterized by transmission electron microscopy (TEM), Fourier transform infrared analysis (FTIR), thermogravimetric analysis (TGA) and elemental analysis (EA). An effective dispersive solid-phase ext ...
DOI:
10.1016/j.chroma.2011.06.090

18. Removal of sample background buffering ions and myoglobin enrichment via a pH junction created by discontinuous buffers in capillary electrophoresis

Author:
Booker, Christina J.; Sun, Samuel; Woolsey, Sarah; Mejia, Jose S.; Yeung, Ken K.-C.
Source:
Journal of chromatography 2011 v.1218 no.33 pp. 5705-5711
ISSN:
0021-9673
Subject:
buffers; capillary electrophoresis; chromatography; ionic strength; ions; myoglobin; pH; salt concentration; sodium phosphate
Abstract:
... Traditional CE sample stacking is ineffective for samples containing a high concentration of salt and/or buffer. We recently reported the use of a discontinuous buffer system for protein enrichment that was applicable to samples containing millimolar concentrations of salt. In this paper, the technique was investigated for samples containing unwanted buffering ions, including TRIS, MES, and phosph ...
DOI:
10.1016/j.chroma.2011.06.054

19. Ruggedness and robustness of conversion factors in method of simultaneous determination of multi-components with single reference standard

Author:
Hou, Jin-Jun; Wu, Wan-Ying; Da, Juan; Yao, Shuai; Long, Hua-Li; Yang, Zhou; Cai, Lu-Ying; Yang, Min; Liu, Xuan; Jiang, Bao-Hong; Guo, De-An
Source:
Journal of chromatography 2011 v.1218 no.33 pp. 5618-5627
ISSN:
0021-9673
Subject:
Oriental traditional medicine; Salvia miltiorrhiza; chromatography; quality control; wavelengths
Abstract:
... Single standard to determine multi-components (SSDMC) is a novel and rational method for quality control of botanical products and traditional Chinese medicines (TCMs). However, it is restricted to wide application due to unknown fluctuation in conversion factors when it is performed in different laboratories. To evaluate the fluctuations of conversion factors, we selected Salvia miltiorrhiza as a ...
DOI:
10.1016/j.chroma.2011.06.058

20. Selective extraction of alkaloids in human urine by on-line single drop microextraction coupled with sweeping micellar electrokinetic chromatography

Author:
Gao, Wenhua; Chen, Gaopan; Chen, Yaowen; Li, Nana; Chen, Tufeng; Hu, Zhide
Source:
Journal of chromatography 2011 v.1218 no.33 pp. 5712-5717
ISSN:
0021-9673
Subject:
alkaloids; humans; hydrodynamics; micellar electrokinetic capillary chromatography; microextraction; mixing; sodium hydroxide; temperature; urine
Abstract:
... A novel method of on-line single drop microextraction (SDME) coupled with sweeping micellar electrokinetic chromatography (MEKC) for the selective extraction and dual preconcentration of alkaloids was developed. In this technique, analytes of three alkaloids were firstly extracted from 4.0mL basic aqueous sample solution (donor phase, 500mM NaOH) into a layer of n-octanol at temperature 30°C with ...
DOI:
10.1016/j.chroma.2011.06.074