Preparation of a new C18 stationary phase containing embedded urea groups for use in high-performance liquid chromatography

Silva, César Ricardo; Bachmann, Stefan; Schefer, Renata Rabelo; Albert, Klaus; Jardim, Isabel Cristina Sales Fontes; Airoldi, Cláudio

doi:10.1016/s0021-9673(01)01263-8

Cited by 46 publications

(16 citation statements)

References 21 publications

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“…O-Terphenyl and triphenylene were separated with a higher shape selectivity (a T/O ) of 3.10 when compared with ZORBAX Eclipse XDB-C18 (a T/O 1.47) and other reported columns [15]. The possible reason was largely due to the presence of polar-embedded group, and certain intermolecular interactions that existed between the func- (14) were obtained well separated, which typically cannot be achieved on C18 stationary phases [24]. From Fig.…”

Section: Chromatographic Testsmentioning

confidence: 89%

Preparation of a stationary phase with s‐triazine ring embedded group for reversed phase high‐performance LC

Dai

et al. 2010

J of Separation Science

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A preparative high-speed counter-current chromatography method for isolation and purification of bufadienolides from ChanSu was developed by using a stepwise elution with two-phase solvent system composed of n-hexane/ethyl acetate/methanol/water at the ratios of 4:6:2:4 v/v, 4:6:2.5:4 v/v and 4:6:3.2:4 v/v. A total of 3.8 mg of gamabufotalin (1), 7.2 mg of arenobufagin (2), 3.4 mg of telocinobufagin (3), 5.3 mg of bufotalin (4), 8.5 mg of cinobufotalin (5) and 8 mg of bufalin (6) were obtained in one-step separation from 80 mg of the crude extract with purity of 92.7, 96.7, 87.2, 97.3, 94.9 and 99.4%, respectively. Their chemical structures were identified on the basis of (1)H-NMR and (13)C-NMR technology.

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Section: Chromatographic Testsmentioning

confidence: 89%

Preparation of a stationary phase with s‐triazine ring embedded group for reversed phase high‐performance LC

Dai

et al. 2010

J of Separation Science

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“…The chromatographic separations of CLO and DOX were performed using a 125 mm x 3.9 mm i.d. column packed with a C8 urea stationary phase containing an embedded urea (polar) group prepared in our laboratory by a modification of the procedure from preparation of stationary phases with polar groups (Silva et al, 2001(Silva et al, , 2002(Silva et al, , 2003. The injection volume to carry out the chromatography was set at 5 mL.…”

Section: Chromatographic Instrument and Conditionsmentioning

confidence: 99%

“…Some mechanisms that have been proposed are the interaction of the polar function with the unwanted silanols through hydrogen bonding and an increase in the water concentration on the surface because of the hydrogen bonding ability of the polar groups. As a result, the surface layer should have a higher dielectric constant, weakening the interactions between residual surface silanols and basic analytes (Silva et al, 2002). Another advantage is that the phase containing embedded polar groups requires a mobile phase with a lower concentration of organic solvent (Silva et al, 2001).…”

Section: Optimization Of the Chromatographic Conditionsmentioning

confidence: 99%

Simultaneous determination of clobutinol hydrochloride and doxylamine succinate from syrups by RP HPLC using a new stationary phase containing embedded urea polar groups

Rosa

Jardim

2012

Braz. J. Pharm. Sci.

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A new, simple, fast, reproducible and sensitive reversed phase HPLC method, using a new stationary phase containing embedded urea polar groups, has been developed and validated for the simultaneous determination of clobutinol hydrochloride (CLO) and doxylamine succinate (DOX) in syrups. The determination was carried out on a C8 urea column (125 mm x 3.9 mm i.d., 5 mm particle size) synthetized at the Liquid Chomatography Laboratory (LabCrom) of the Chemistry Institute of Unicamp. The mobile phase consisted of a mixture of acetonitrile:methanol:phosphate buffer (pH 2.5) in the gradient mode. The diode array detector (DAD) was operated at 230 nm for CLO and 262 nm for DOX. The method showed adequate precision, with relative standard deviations (RSD) less than 1%. The presence of the excipients did not interfere in the results of the analysis. Accuracy was determined by adding standards of the drugs to a placebo and good recovery values were obtained. The analytical curves were linear (r 2 0.9999 for CLO and 0.9998 for DOX) over a wide concentration range (2.4-336 μg mL -1 for CLO and 2.3-63 μg mL -1 for DOX). The solutions were stable for at least 72 hours at room temperature. The criteria for validation using the ICH guidelines were fulfilled.Uniterms: Clobutinol hydrochloride/determination. Doxylamine succinate/determination. High performance liquid chromatogralhy/quantitative analysis.Um novo método simples, fácil e reprodutível, de fase reversa para CLAE, usando uma fase estacionária contendo um grupo polar, uréia, embutido, foi desenvolvido e validado para determinação simultânea de cloridrato de clobutinol (CLO) e succinato de doxilamina (DOX) em xarope. A determinação foi realizada em uma coluna C8 uréia (125 mm x 3,9 mm d.i., 5 mm tamanho de partícula) sintetizada em nosso laboratório (LabCrom). A fase móvel consistiu de mistura de acetonitrila:metanol:tampão fosfato pH 2,5, em eluição por gradiente. O detector por arranjos de diodo (DAD) foi utilizado a 230 nm para CLO e a 262 nm para DOX. O método apresentou precisão adequada, com desvio padrão relativo menor que 1%. A presença de excipientes não interferiu nos resultados obtidos. A exatidão foi realizada pela adição dos padrões dos fármacos ao placebo e valores de recuperação aceitáveis foram obtidos. As curvas analíticas mostraram-se lineares (r 2 0,9999 para CLO e 0,9998 para DOX) em uma ampla faixa de concentração (2,4-336 μg mL -1 para CLO e 2,3-63 μg mL -1 para DOX). A solução padrão foi estável por 72 horas a temperatura ambiente. Os parâmetros de validação foram realizados conforme o guia ICH.

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“…The lower pressure drop of the TDAS monolithic column reflects the high porosity and the large macropores, which resulted in high permeabilities. Stationary phases containing embedded polar groups have been developed to improve the peak shape of basic compounds and allow for their use in highly aqueous conditions in HPLC [31,32]. These phases provide several advantages in comparison to ODS packings, such as excellent peak shapes for basic compounds, good compatibility with highly aqueous mobile phases, different selectivities [33].…”

Section: Electrochromatographymentioning

confidence: 99%

Development of a new C₁₄ monolithic silica column containing embedded polar groups for pressurized capillary electrochromatography

Zhao

2007

J of Separation Science

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Monolithic columns have been prepared with a novel bonded silica stationary phase, tetradecylamine bonded silica (TDAS), and used in pressurized capillary electrochromatography (pCEC). The monolithic silica column matrix was prepared by a sol-gel process and then chemically modified with the spacer (3-glycidoxypropyl)trimethoxysilane and tetradecylamine. The introduced embedded polar amine groups dominated the charge on the surface of the monolithic stationary phase and generated an EOF from cathode to anode under acidic conditions. The tetradecyl hydrophobic chains in TDAS provide chromatographic interactions. The chromatographic characteristics of the prepared monolithic column were studied. Some aromatic compounds including alkylbenzenes, aromatic hydrocarbons, phenols, and anilines were successfully separated on the TDAS monolithic column in pCEC mode. As expected, the TDAS monolithic stationary phases exhibit typical reversed-phase electrochromatographic behavior toward neutral solutes due to the introduced tetradecyl groups. Hydrophobic as well as electrophoretic migration processes within the monoliths were observed in the separation of basic anilines. Symmetrical peaks can be obtained for anilines because the embedded polar amine groups on the surface can effectively shield the adsorption of positively charged analytes onto the stationary phase.

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Preparation of a new C18 stationary phase containing embedded urea groups for use in high-performance liquid chromatography

Cited by 46 publications

References 21 publications

Preparation of a stationary phase with s‐triazine ring embedded group for reversed phase high‐performance LC

Preparation of a stationary phase with s‐triazine ring embedded group for reversed phase high‐performance LC

Simultaneous determination of clobutinol hydrochloride and doxylamine succinate from syrups by RP HPLC using a new stationary phase containing embedded urea polar groups

Development of a new C₁₄ monolithic silica column containing embedded polar groups for pressurized capillary electrochromatography

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Preparation of a new C18 stationary phase containing embedded urea groups for use in high-performance liquid chromatography

Cited by 46 publications

References 21 publications

Preparation of a stationary phase with s‐triazine ring embedded group for reversed phase high‐performance LC

Preparation of a stationary phase with s‐triazine ring embedded group for reversed phase high‐performance LC

Simultaneous determination of clobutinol hydrochloride and doxylamine succinate from syrups by RP HPLC using a new stationary phase containing embedded urea polar groups

Development of a new C14 monolithic silica column containing embedded polar groups for pressurized capillary electrochromatography

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Development of a new C₁₄ monolithic silica column containing embedded polar groups for pressurized capillary electrochromatography