Method development and validation for optimised separation of salicylic, acetyl salicylic and ascorbic acid in pharmaceutical formulations by hydrophilic interaction chromatography and response surface methodology

Publication year: 2011Source: Journal of Chromatography A, In Press, Accepted Manuscript, Available online 12 June 2011Nader, Hatambeygi , Ghazaleh, Abedi , Mohammad, TalebiThis paper introduces a design of experiments (DOE) approach for method optim…

Publication year: 2011
Source: Journal of Chromatography A, In Press, Accepted Manuscript, Available online 12 June 2011

Nader, Hatambeygi , Ghazaleh, Abedi , Mohammad, Talebi

This paper introduces a design of experiments (DOE) approach for method optimisation in hydrophilic interaction chromatography (HILIC). An optimisation strategy for the separation of acetylsalicylic acid, its major impurity salicylic acid and ascorbic acid in pharmaceutical formulations by HILIC is presented, with the aid of response surface methodology (RSM) and Derringer's desirability function. A Box-Behnken experimental design was used to build the mathematical models and then to choose the significant parameters for the optimisation by simultaneously taking both resolution and retention time as the responses. The refined model had a satisfactory coefficient (R2>0.92, n=27). The four independent variables studied simultaneously...

Modelling oligomer formation in chromatographic separations

Publication year: 2011Source: Journal of Chromatography A, In Press, Accepted Manuscript, Available online 12 June 2011Jørgen M., MollerupOligomer forms of proteins are formed by self and cross association or complex formation with ligands. Modelling …

Publication year: 2011
Source: Journal of Chromatography A, In Press, Accepted Manuscript, Available online 12 June 2011

Jørgen M., Mollerup

Oligomer forms of proteins are formed by self and cross association or complex formation with ligands. Modelling studies using an ion-exchange adsorbent have demonstrated that the formation of an oligomer form of a target protein can improve a chromatographic separation because the oligomer form displaces the impurities. The results of the investigation show that the process is very robust, that the purity, the yield, and the productivity increase with increasing load and increasing salt concentration in the eluant. An impurity level less than 1ppm is easy to achieve having a yield of 98%.A universal model for the adsorption equilibria of...

Simultaneous determination of bisphenol A and alkylphenol in plant oil by gel permeation chromatography and isotopic dilution liquid chromatography tandem mass spectrometry

Publication year: 2011Source: Journal of Chromatography A, In Press, Accepted Manuscript, Available online 12 June 2011Yumin, Niu , Jing, Zhang , Yongning, Wu , Bing, ShaoA simple analytical method was developed for the simultaneous analysis of bisp…

Publication year: 2011
Source: Journal of Chromatography A, In Press, Accepted Manuscript, Available online 12 June 2011

Yumin, Niu , Jing, Zhang , Yongning, Wu , Bing, Shao

A simple analytical method was developed for the simultaneous analysis of bisphenol A (BPA), nonylphenol (NP) and octylphenol (OP) in plant oil. The target compounds were extracted by cyclohexane/ethyl acetate (1:1), purified by gel permeation chromatography (GPC), and analyzed by liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) in the negative ion mode. An isolator column was attached in front of the injection valve of the LC to separate background contaminants. Recovery studies were performed at three fortification levels. Mean recoveries were from 92.9% to 119.0%, with an acceptable coefficient of variation (4.4–18.5%, n=6). The limits of quantification of the...

SPIRAL COUNTER-CURRENT CHROMATOGRAPHY OF SMALL MOLECULES, PEPTIDES AND PROTEINS USING THE SPIRAL TUBING SUPPORT ROTOR

Publication year: 2011Source: Journal of Chromatography A, In Press, Accepted Manuscript, Available online 12 June 2011Martha, Knight , Thomas M., Finn , John, Zehmer , Adam, Clayton , Aprile, PilonAn important advance in countercurrent chromatogra…

Publication year: 2011
Source: Journal of Chromatography A, In Press, Accepted Manuscript, Available online 12 June 2011

Martha, Knight , Thomas M., Finn , John, Zehmer , Adam, Clayton , Aprile, Pilon

An important advance in countercurrent chromatography (CCC) carried out in open flow-tubing coils, rotated in planetary centrifuges, is the new design to spread out the tubing in spirals. More spacing between the tubing was found to significantly increase the stationary phase retention, such that now all types of two-phase solvent systems can be used for liquid-liquid partition chromatography in the J-type planetary centrifuges. A spiral tubing support (STS) frame with circular channels was constructed by laser sintering technology into which FEP tubing was placed in 4 spiral loops per layer from the bottom to the top and a cover affixed...

Model simulation and experimental verification of a cation-exchange IgG capture step in batch and continuous chromatography

Publication year: 2011Source: Journal of Chromatography A, In Press, Accepted Manuscript, Available online 12 June 2011T., Müller-Späth , G., Ströhlein , L., Aumann , H., Kornmann , P., Valax , …The cation-exchange capture step of a monoclonal…

Publication year: 2011
Source: Journal of Chromatography A, In Press, Accepted Manuscript, Available online 12 June 2011

T., Müller-Späth , G., Ströhlein , L., Aumann , H., Kornmann , P., Valax , ...

The cation-exchange capture step of a monoclonal antibody (mAb) purification process using single column batch and multicolumn continuous chromatography (MCSGP) was modeled with a lumped kinetic model. Model parameters were experimentally determined under analytical and preparative conditions: Porosities, retention factors and mass transfer parameters of purified mAb were obtained through a systematic procedure based on retention time measurements. The saturation capacity was determined through peak fitting assuming a Langmuir-type adsorption isotherm. The model was validated using linear batch gradient elutions. In addition, the model was used to simulate the start-up, cyclic steady state and shut down behavior of the continuous...

Preparation and characterization of lauryl methacrylate-based monolithic microbore column for reversed-phase liquid chromatography

Publication year: 2011Source: Journal of Chromatography A, In Press, Accepted Manuscript, Available online 12 June 2011Shin, Shu , Hiroharu, Kobayashi , Norihisa, Kojima , Akhmad, Sabarudin , Tomonari, UmemuraPoly(lauryl methacrylate-co-ethylene di…

Publication year: 2011
Source: Journal of Chromatography A, In Press, Accepted Manuscript, Available online 12 June 2011

Shin, Shu , Hiroharu, Kobayashi , Norihisa, Kojima , Akhmad, Sabarudin , Tomonari, Umemura

Poly(lauryl methacrylate-co-ethylene dimethacrylate) monoliths were in situ synthesized within the confines of a silicosteel tubing of 1.02mm i.d. and 1/16" o.d for microbore reversed-phase HPLC. In order to obtain practically useful monoliths with adequate column efficiency, low flow resistance, and good mechanical strength, some parameters such as total monomer concentration (%T), cross-linking degree (%C) and polymerization temperature were optimized. High-efficiency monoliths were successfully obtained by thermal polymerization of a monomer mixture (40%T, 10%C) with a binary porogenic solvent consisting of 1-propanol and 1,4-butandiol (7:4, v/v) at a high temperature of 90°C. The morphology and porous structure of the resulting monoliths...

Direct and simultaneous determination of representative byproducts in a lignocellulosic hydrolysate of corn stover via GC-MS with a Deans switch

Publication year: 2011Source: Journal of Chromatography A, In Press, Accepted Manuscript, Available online 12 June 2011Rongping, Zheng , Hongman, Zhang , Jing, Zhao , Mingliu, Lei , He, HuangPretreatment is one of the most important steps in produc…

Publication year: 2011
Source: Journal of Chromatography A, In Press, Accepted Manuscript, Available online 12 June 2011

Rongping, Zheng , Hongman, Zhang , Jing, Zhao , Mingliu, Lei , He, Huang

Pretreatment is one of the most important steps in producing fuel ethanol from lignocellulosic biomass. Simple, fast and accurate quantification of byproducts in lignocellulosic hydrolysates is critical to optimize the pretreatment procedures, but still a challenge. In this paper, a new GC-MS (SIM) method based on a Deans switch has been developed for the determination of byproducts in a corn stover hydrolysate. The Deans switch was incorporated into a hardware system that facilitated the direct aqueous injection (DAI) on GC-MS system. Simultaneous chromatographic separation and quantification of 18 byproducts including four aliphatic acids, five furan derivatives, four phenolic compounds and...

Comparing columns for gas chromatography with the two-parameter model for retention prediction

Publication year: 2011Source: Journal of Chromatography A, In Press, Accepted Manuscript, Available online 12 June 2011Yasar, Thewalim , Ioannis, Sadiktsis , Anders, ColmsjöThe retention times of selected compounds in temperature programmed gas chro…

Publication year: 2011
Source: Journal of Chromatography A, In Press, Accepted Manuscript, Available online 12 June 2011

Yasar, Thewalim , Ioannis, Sadiktsis , Anders, Colmsjö

The retention times of selected compounds in temperature programmed gas chromatography were predicted using a two-parameter model, on the basis of thermodynamic data obtained from isothermal runs on seven capillary columns, primarily substituted with 5% diphenylsiloxane.The scope for using thermodynamic data obtained from isothermal runs on one column to optimize separation on a different column or a different instrument setup was investigated. Additionally, the predictive utility of thermodynamic data obtained using a DB-5 column that had been in use for three years was compared to that of a new column of the same model. It was found that satisfactory separation...

Simultaneous determination of benzotriazoles and ultraviolet filters in ground water, effluent and biosolid samples using gas chromatography-tandem mass spectrometry

Publication year: 2011Source: Journal of Chromatography A, In Press, Accepted Manuscript, Available online 12 June 2011You-Sheng, Liu , Guang-Guo, Ying , Ali, Shareef , Rai S., KookanaA new method using gas chromatography-tandem mass spectrometry (G…

Publication year: 2011
Source: Journal of Chromatography A, In Press, Accepted Manuscript, Available online 12 June 2011

You-Sheng, Liu , Guang-Guo, Ying , Ali, Shareef , Rai S., Kookana

A new method using gas chromatography-tandem mass spectrometry (GC-MS/MS) was developed for the determination of four benzotriazoles i.e. benzotriazole (BT), 5-methylbenzotriazole (5-TTri), 5-chlorobenzotriazole (CBT), 5,6-dimethylbenzotriazole (XTri)), and six UV filters i.e. benzophenone-3 (BP-3), 3-(4-methylbenzylidene)camphor (4-MBC), octyl 4-methoxycinnamate (OMC), 2-(3-t-butyl-2-hydroxy-5-methylphenyl)-5-chloro benzotriazole (UV-326), 2-(2’-Hydroxy-5’-octylphenyl)-benzotriazole (UV-329), octocrylene (OC) in ground water, effluent and biosolid samples. Solid phase extraction (SPE) and pressurized liquid extraction (PLE) were applied as the preconcentration method for water samples (ground water and effluent) and biosolid samples, respectively. The optimized method allowed us to quantify all target compounds with the method detection limits ranging from 0.29 to 11.02ng/L, 0.5 to...

DETERMINATION OF PARABENS IN HOUSE DUST BY PRESSURISED HOT WATER EXTRACTION FOLLOWED BY STIR BAR SORPTIVE EXTRACTION AND THERMAL DESORPTION-GAS CHROMATOGRAPHY-MASS SPECTROMETRY

Publication year: 2011Source: Journal of Chromatography A, In Press, Accepted Manuscript, Available online 12 June 2011Noelia, Ramírez , Rosa Maria, Marcé , Francesc, BorrullThis study describes the development of a new method for determining p-hyd…

Publication year: 2011
Source: Journal of Chromatography A, In Press, Accepted Manuscript, Available online 12 June 2011

Noelia, Ramírez , Rosa Maria, Marcé , Francesc, Borrull

This study describes the development of a new method for determining p-hydroxybenzoic esters (parabens) in house dust. This optimised method was based on the pressurised hot water extraction (PHWE) of house dust, followed by the acetylation of the extracted parabens, stir bar sorptive extraction (SBSE) with a polydimethylsiloxane stir bar, and finally analysis using thermal desorption–gas chromatography–mass spectrometry (TD-GC-MS). The combination of SBSE after PHWE allows the analytes to be preconcentrated and extracted from the aqueous extract in a single step with minimal manipulation of the sample. Furthermore the in situ acetylation of parabens prior to SBSE improved their extraction...

Liquid phase microextraction applications in food analysis

Publication year: 2011Source: Journal of Chromatography A, In Press, Accepted Manuscript, Available online 7 June 2011María, Asensio-Ramos , Lidia M., Ravelo-Pérez , Miguel Ángel, González-Curbelo , Javier, Hernández-BorgesOver the last years, …

Publication year: 2011
Source: Journal of Chromatography A, In Press, Accepted Manuscript, Available online 7 June 2011

María, Asensio-Ramos , Lidia M., Ravelo-Pérez , Miguel Ángel, González-Curbelo , Javier, Hernández-Borges

Over the last years, liquid-phase microextraction (LPME) in its different application modes (single drop microextraction, dispersive liquid-liquid microextraction and hollow fiber-LPME) has been increasingly applied for the extraction of both inorganic and organic analytes from different matrices. Its advantages over conventional extraction procedures (simplicity, effectiveness, rapidity and low consumption of organic solvents) has also attracted its application in the complex food analysis field, in which it has clearly provided good and challenging results. A comprehensive review dealing with those articles published since its introduction till the end of March 2011 is presented, offering also a critical vision of the analytical...

Morphological analysis of physically reconstructed capillary hybrid silica monoliths and correlation with separation efficiency

Publication year: 2011Source: Journal of Chromatography A, In Press, Accepted Manuscript, Available online 1 June 2011Stefan, Bruns , Takeshi, Hara , Bernd M., Smarsly , Ulrich, TallarekWe report an experimental study on the structural (especially r…

Publication year: 2011
Source: Journal of Chromatography A, In Press, Accepted Manuscript, Available online 1 June 2011

Stefan, Bruns , Takeshi, Hara , Bernd M., Smarsly , Ulrich, Tallarek

We report an experimental study on the structural (especially radial) heterogeneity of eleven 100μm i.d. capillary tetramethoxysilane-methyltrimethoxysilane hybrid silica monoliths with different pore and skeleton sizes, which were imaged by an optimized confocal laser scanning microscopy method. This method allows the optical sectioning of the monoliths, which is a prerequisite for quantitative morphological image analysis. Both radial porosity profiles and chord length distributions were calculated in the macropore domain for each column from at least 100 complete cross-sectional views along the column axis. The statistical approach visualized radial heterogeneities on different length scales in the monolithic structures. Chord length distributions...

On-line concentration sample stacking coupled with water-in-oil microemulsion electrokinetic chromatography

Publication year: 2011Source: Journal of Chromatography A, In Press, Accepted Manuscript, Available online 1 June 2011Hsi-Ya, Huang , Wan-Ling, Liu , Brenda, Singco , Shih-Huan, Hsieh , Yung-Han, ShihThis study describes for the first time, the abi…

Publication year: 2011
Source: Journal of Chromatography A, In Press, Accepted Manuscript, Available online 1 June 2011

Hsi-Ya, Huang , Wan-Ling, Liu , Brenda, Singco , Shih-Huan, Hsieh , Yung-Han, Shih

This study describes for the first time, the ability of a normal stacking mode (NSM) on-line concentration step coupled with water-in-oil (W/O) microemulsion electrokinetic chromatography (MEEKC), using six common penicillin antibiotics (oxacillin, penicillin V, penicillin G, nafcillin, ampicillin, and amoxicillin) as test analytes. Optimization of penicillin separation in the conventional W/O MEEKC system demonstrated that change in the type and concentration of the oil phase (1-butanol) and column temperature had a pronounced effect on the separation. With the subsequent development of the NSM coupled with W/O MEEKC, improved separation and detection sensitivities were observed when an organic solvent plug (1-propanol;...

Application of multiwall carbon nanotubes-based matrix solid phase dispersion extraction for determination of hormones in butter by gas chromatography mass spectrometry

Publication year: 2011Source: Journal of Chromatography A, In Press, Accepted Manuscript, Available online 1 June 2011Rui, Su , Xinghua, Wang , Xu, Xu , Ziming, Wang , Dan, Li , …The multiwall carbon nanotubes (MWCNTs)-based matrix solid phase di…

Publication year: 2011
Source: Journal of Chromatography A, In Press, Accepted Manuscript, Available online 1 June 2011

Rui, Su , Xinghua, Wang , Xu, Xu , Ziming, Wang , Dan, Li , ...

The multiwall carbon nanotubes (MWCNTs)-based matrix solid phase dispersion (MSPD) was applied for the extraction of hormones, including 17-α-ethinylestradiol, 17-α-estradiol, estriol, 17-β-estradiol, estrone, medroxyprogesterone, progesterone and norethisterone acetate in butter samples. The method includes MSPD extraction of the target analytes from butter samples, derivatization of hormones with heptafluorobutyric acid anhydride-acetonitrile mixture, and determination by gas chromatography-mass spectrometry. The mixture containing 0.30g graphitized MWCNTs and 0.10g MWCNTs was selected as absorbent. Ethyl acetate was used as elution solvent. The elution solvent volume and flow rate were 12mL and 0.9mLmin−1 respectively. The recoveries of hormones obtained by analyzing the five spiked butter...

Speciation analysis of arsenic compounds in edible oil by ion chromatography – inductively coupled plasma mass spectrometry

Publication year: 2011Source: Journal of Chromatography A, In Press, Accepted Manuscript, Available online 1 June 2011Yun-Ling, Chu , Shiuh-Jen, JiangAn inductively coupled plasma mass spectrometer (ICP-MS) was used as an ion chromatographic (IC) dete…

Publication year: 2011
Source: Journal of Chromatography A, In Press, Accepted Manuscript, Available online 1 June 2011

Yun-Ling, Chu , Shiuh-Jen, Jiang

An inductively coupled plasma mass spectrometer (ICP-MS) was used as an ion chromatographic (IC) detector for the speciation analysis of arsenic in edible oil. The arsenic species studied include arsenite, arsenate, monomethylarsonic acid, dimethylarsinic acid, arsenobetaine and arsenocholine. Gradient elution using (NH4)2CO3 and methanol at pH 8.5 allowed the chromatographic separation of all species in less than 8minutes. Effluents from the IC column were delivered to the nebulizer of ICP-MS for the determination of arsenic. The concentrations of arsenic species have been determined in several used and fresh vegetable oil samples. In this study, a microwave-assisted extraction method was used...

The inuence of the memory e_ect on preparative sep arations using the amylose tris(3,5-dimethylphenylcarbamate) stationary phase

Publication year: 2011Source: Journal of Chromatography A, In Press, Accepted Manuscript, Available online 1 June 2011Joel, Putnam , Georges, GuiochonAcid/base mobile phase modi_ers a_ect enantioseparations in ways that are not yet under6 stood for th…

Publication year: 2011
Source: Journal of Chromatography A, In Press, Accepted Manuscript, Available online 1 June 2011

Joel, Putnam , Georges, Guiochon

Acid/base mobile phase modi_ers a_ect enantioseparations in ways that are not yet under6 stood for the lack of systematic studies, which makes the scale-up of preparative separations di_cult to predict. Shifts of the selectivity of certain pairs of enantiomers upon exposure of the column to these modi_ers is amply documented. Furthermore, once the modi_er has been removed from the mobile phase, the improved selectivity remains, this phenomenon has been named the memory e_ect. We selected four enantiomeric pairs for a systematic study of this memory e_ect. The selectivity of 4-chlorophenylalanine ethyl ester (4CPEE) improves after a solution of ethanesulfonic acid...

Annealing of silica to reduce the concentration of isolated silanols and peak tailing in reverse phase liquid chromatography

Publication year: 2011Source: Journal of Chromatography A, In Press, Accepted Manuscript, Available online 1 June 2011Josh J., Newby , Michael A., Legg , Benjamin, Rogers , Mary J., WirthNon-porous, colloidal silica particles were annealed at three …

Publication year: 2011
Source: Journal of Chromatography A, In Press, Accepted Manuscript, Available online 1 June 2011

Josh J., Newby , Michael A., Legg , Benjamin, Rogers , Mary J., Wirth

Non-porous, colloidal silica particles were annealed at three different temperatures, 800, 900 and 1050°C. The adsorption of lysozyme, a probe of surface roughness, was consistent with progressively reduced surface roughness as temperature increased. The heat treated silica particles were rehydroxylated and then used to pack UHPLC columns. The cationic protein lysozyme was used to probe silanol activity, which exhibited progressively less tailing as the annealing temperature increased. FTIR spectroscopy confirmed that the abundance of isolated silanols on the surface was reduced by annealing at 900°C or 1050°C. FTIR also revealed that there was markedly increased hydrogen bonding of the isolated...

high-performance liquid chromatography COUPLED to direct analysis in real time mass spectrometry: INVESTIGATIONS ON GRADIENT ELUTION AND influence of complex matrices on signal intensities

Publication year: 2011Source: Journal of Chromatography A, In Press, Accepted Manuscript, Available online 1 June 2011Susanne, Beißmann , Wolfgang, Buchberger , Robert, Hertsens , Christian W., KlampflDirect analysis in real time (DART) time-of-fli…

Publication year: 2011
Source: Journal of Chromatography A, In Press, Accepted Manuscript, Available online 1 June 2011

Susanne, Beißmann , Wolfgang, Buchberger , Robert, Hertsens , Christian W., Klampfl

Direct analysis in real time (DART) time-of-flight mass spectrometry (TOF-MS) has been tested for its suitability as a detector for gradient elution HPLC. Thereby a strong dependency of signal intensity on the amount of organic solvent present in the eluent could be observed. Adding a make-up liquid (iso-propanol) post-column to the HPLC effluent greatly enhanced detection limits for early eluting compounds. Limits of detection achieved employing this approach were in the range of 7–27μgL−1 for the parabene test mixture and 15–87μgL−1 for the pharmaceuticals. In further investigations DART ionization was compared to several other widely used atmospheric pressure ionization methods...