Evaluation of carrier electrolytes for capillary zone electrophoresis of low-molecular-mass anions with indirect UV detection

Cousins, Sarah M.; Haddad, Paul R.; Buchberger, Wolfgang

doi:10.1016/0021-9673(94)80266-1

Cited by 80 publications

(27 citation statements)

References 5 publications

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“…As most of the aliphatic organic acids exhibit little or no UV absorption, indirect UV detection is normally carried out using BGEs containing chromophores, such as chromate [23][24][25], phthalate [26,27], benzoate [28], 2,6-pyridine dicarboxylic acid [29], trimellitate [30], pyromellitate [31] and naphthalene sulfonate [32]. For the separation of oxalate, citrate and tartrate, potassium chromate (pH 8.1, 5 mM) was tested as BGE.…”

Section: Composition Of the Bgementioning

confidence: 99%

Capillary electrochromatographic analysis of aliphatic mono‐ and polycarboxylic acids

et al. 2003

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The parameters influencing the electrochromatographic separation of aliphatic organic acids in a capillary column with a wall-coated macrocyclic polyamine have been studied. Indirect detection using chromate, pyromellitate, trimellitate, o-phthalate, benzoate and acetate as background electrolytes has been tested. A complete separation of polyprotic acids could be achieved with pyromellitate buffer (7.5 mM, pH 6.5), and satisfactory results for the simultaneous separation of monoprotic acids and polyprotic acids were found using a capillary column of 70 cm (50 cm effective length)x75 microm inner diameter, electrokinetic injection (-10 kV, 10 s), benzoate buffer (6 mM, pH 4.6), separation voltage of -10 kV, and detection at 220 nm. For the separation of the geometric isomers fumarate and maleate, acetate buffer was found the best choice among the background electrolytes tested. The method so established has been applied to the determination of organic acids in soy sauce, brandy, lemon juice, spinach juice and cigarette. From the retention behavior, it was found that the separation mechanism on the bonded phase was influenced by the macrocyclic effect, electrostatic attraction, hydrogen bonding, van der Waals forces, and anion exchange, in addition to the differences in electrophoretic mobility.

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Section: Composition Of the Bgementioning

confidence: 99%

Capillary electrochromatographic analysis of aliphatic mono‐ and polycarboxylic acids

et al. 2003

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“…Várias abordagens têm sido propostas para otimização das condições de análise de ânions por eletroforese capilar 11,[15][16][17][79][80][81][82][83][84][85][86][87] . Embora muitos destes trabalhos apresentem estudos fragmentados sobre o efeito parcial de algumas variáveis do sistema, todos fornecem informações fundamentais para subsidiar o desenvolvimento de metodologia adequada, como requerem amostras de matrizes complexas, por exemplo, e são satisfatórios em uma dada extensão.…”

Section: Comentários Finaisunclassified

Determinação simultânea de ânions por eletroforese capilar: características e aplicações

Colombara¹,

Tavares²,

Massaro³

1997

Quím. Nova

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Recebido em 20/11/96; aceito em 22/03/97 SIMULTANEOUS DETERMINATION OF ANIONS BY CAPILLARY ELECTROPHORESIS:CHARACTERISTICS AND APPLICATIONS. Capillary electrophoresis (CE) encompasses a number of characteristics quite suitable for the simultaneous analysis of small ions such as high efficiency and resolving power, directly associated to its impressively high peak capacity, and short analysis time. In appropriate conditions, it is possible to perform the separation of approximately 36 anions in less than 3 minutes. In this work, the mechanisms by which anion analysis is performed was criteriously discussed, and a thorough review of the literature in the past 5 years, focusing mostly in applications of CE to anion analysis in real matrices, was presented.Keywords: capillary electrophoresis; ion analysis; anion. REVISÃO INTRODUÇÃOA determinação analítica de ânions encontra extensa aplicação em vários segmentos da indústria (química, farmacêutica, alimentícia, etc.), bem como na caracterização de amostras biológicas e ambientais 1 . A análise individual de ânions pode ser feita por métodos volumétricos, gravimétricos, espectrofotomé-tricos e eletroanalíticos 2,3 . Já para análise simultânea de ânions, geralmente são empregados métodos cromatográficos [3][4][5] . A cromatografia iônica (CI) 4 com detecção condutométrica é empregada principalmente para ânions inorgânicos e alguns orgâni-cos de cadeia curta, enquanto que, para os ânions derivados de ácidos orgânicos de cadeias maiores, é utilizada a cromatografia líquida de alta eficiência (CLAE) 5 . Na última década, a eletroforese capilar (EC) 6 vem sendo apontada como uma alternativa bastante atraente para a determinação simultânea de ânions. Ela tem se distinguido das demais técnicas utilizadas para o mesmo fim, principalmente no que se refere à versatilidade e simplicidade. Existem inúmeros trabalhos de comparação na literatura, tanto de EC versus CI, especificamente 7-11 , quanto de EC versus CLAE 12-14 . Nestes trabalhos as técnicas são avaliadas com relação a diversos aspectos. Talvez o mais importante seja a eficiência da coluna, que se reflete na capacidade de pico (número máximo de solutos separados numa única corrida) 15 . A figura 1 ilustra este aspecto em particular, na separação de 36 ânions por eletroforese capilar e cromatografia iônica, mostrando de forma inequívoca o alto desempenho da coluna capilar. Os demais aspectos são: custo e durabilidade das colunas 16,17 , necessidade de tratamento prévio da amostra, tempo de análise 18 , volume de amostra 19 , e custo final por análise 20 . A conclusão que prevalece nestes estudos é que a eletroforese capilar apresenta inúmeras vantagens, o que tem contribuído para assegurar uma posição de destaque entre as técnicas analíticas de separação. CARACTERÍSTICAS DA ANÁLISE DE ÂNIONSA separação e identificação de ânions por eletroforese capilar é em geral conduzida em soluções aquosas de eletrólitos, contendo ânions cromóforos e agentes modificadores da superfí-cie capilar. A presença do cromóforo só se faz ne...

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“…These detection methods are based on the addition of a UV absorbing chromophore (probe) to the buffer or the eluent, and the measured signal is generated due to the replacement of the probe by the analyte [11][12][13][14]. In this way, fosfomycin was indirectly detected in serum and aqueous humor after separation by ion-exchange chromatography [15] as well as by CE [4,16].…”

Section: Introductionmentioning

confidence: 99%

Capillary electrophoresis analysis of fosfomycin in biological fluids for clinical pharmacokinetic studies

et al. 2004

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A feasible capillary zone electrophoresis (CZE) method with indirect UV and contactless conductivity detection was developed for the determination of fosfomycin, an antibiotic, in human plasma and microdialysis samples. Samples were collected from test persons during a clinical trial. The background electrolytes used consisted of 25 mM benzoic acid and 0.5 mM hexadecyltrimethylammonium bromide, adjusted with tris(hydroxymethyl)aminomethane solution to pH 6.95 for plasma, and to pH 8.05 for microdialysis samples. CZE separations of the anionic analyte were carried out with reversed electroosmotic flow directed towards the anode. The limit of detection was between 0.6 and 2 microg/mL, depending on the matrix and the detection method. No sample preparation was needed for microdialysis samples; for plasma samples, proteins were precipitated with methanol (1+2, v+v), and the supernatant was analyzed. The yield determined with spiked samples was about 100%, the reproducibility of the entire method, expressed by the RSD% of three independent determinations of fosfomycin in triplicate after spiking Ringer's solutions and plasma samples, respectively, was better than 8%. The method is thus well-suited for clinical studies for the determination of the antibiotic in biological fluids.

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Evaluation of carrier electrolytes for capillary zone electrophoresis of low-molecular-mass anions with indirect UV detection

Cited by 80 publications

References 5 publications

Capillary electrochromatographic analysis of aliphatic mono‐ and polycarboxylic acids

Capillary electrochromatographic analysis of aliphatic mono‐ and polycarboxylic acids

Determinação simultânea de ânions por eletroforese capilar: características e aplicações

Capillary electrophoresis analysis of fosfomycin in biological fluids for clinical pharmacokinetic studies

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