Liquid-phase microextraction based on carrier mediated transport combined with liquid chromatography–mass spectrometry

Ho, Tung Si; Reubsaet, Léon; Anthonsen, Hanne Sofie; Pedersen‐Bjergaard, Stig; Rasmussen, Knut

doi:10.1016/j.chroma.2004.11.078

Cited by 88 publications

(33 citation statements)

References 15 publications

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“…In the three-phase mode, the acceptor solution is commonly an aqueous solution. This mode is suitable for CE, LC, and LC-MS analyses [20][21][22][23]. Now, to demonstrate the potential for LPME-CE, a stereospecific method to analyze HCQ and its metabolites in human urine was developed for the first time.…”

Section: Introductionmentioning

confidence: 98%

Stereoselective determination of hydroxychloroquine and its metabolites in human urine by liquid‐phase microextraction and CE

Oliveira¹,

Cardoso²,

Bonato³

2007

Electrophoresis

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Liquid-phase microextraction based on polypropylene hollow fibers and CE were applied for the chiral determination of hydroxychloroquine (HCQ) and its metabolites (desethylchloroquine, DCQ; desethylhydroxychloroquine, DHCQ; bisdesethylchloroquine, BDCQ) in human urine. The analytes were extracted from 3 mL of urine spiked with the internal standard (metoprolol) and alkalinized with 250 muL of 2 M NaOH. The analytes were extracted into 1-octanol impregnated in the pores of the hollow fiber, and into an acid acceptor solution inside the hollow fiber. The electrophoretic separations were carried out in 100 mmol/L Tris buffer (pH adjusted to 9.0 with phosphoric acid) containing 1% w/v S-beta-CD and 30 mg/mL HP-beta-CD with a constant voltage of +18 kV. The method was linear over the concentration range of 10-1000 ng/mL for each HCQ stereoisomer and 21-333 ng/mL for each metabolite stereoisomer. Within-day and between-day assay precision and accuracy for the analytes were studied at three concentration levels for each stereoisomer and were lower than 15%. The developed method was applied for the determination of the cumulative urinary excretion of HCQ, DCQ, and DHCQ after oral administration of rac-HCQ to a health volunteer. The results obtained are in agreement with previous literature data.

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Section: Introductionmentioning

confidence: 98%

Stereoselective determination of hydroxychloroquine and its metabolites in human urine by liquid‐phase microextraction and CE

Oliveira¹,

Cardoso²,

Bonato³

2007

Electrophoresis

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“…21 Para analitos altamente hidrofílicos, que encontrariam dificuldades em serem extraídos na membrana orgânica apenas pelo processo de difusão, uma outra possibilidade seria a adição de reagente iônico relativamente hidrofóbico à fase doadora ou orgânica, permitindo a formação de par iônico com o analito de interesse, ocorrendo então a extração. [23][24][25] Recentemente, Yazdi e Es'haghi relataram o emprego de tensoativos não-iônicos (ex. : Triton X-100 ® ) adicionados na fase doadora para determinação de drogas de abuso hidrofílicas no cabelo.…”

Section: Figura 1 Representação Esquemática Da Microextração Em Gotaunclassified

Microextração em fase líquida (LPME): fundamentos da técnica e aplicações na análise de fármacos em fluidos biológicos

Oliveira¹,

Magalhães²,

Santana³

et al. 2008

Quím. Nova

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Ribeirão Preto -SP, BrasilRecebido em 1/12/06; aceito em 30/8/07; publicado na web em 26/2/08 LIQUID-PHASE MICROEXTRACTION (LPME): FUNDAMENTALS AND APPLICATIONS TO THE ANALYSIS OF DRUGS IN BIOLOGICAL SAMPLES. The analysis of drugs and metabolites in biological fluids usually requires extraction procedures to achieve sample clean-up and analyte preconcentration. Commonly, extraction procedures are performed using liquid-liquid extraction or solidphase extraction. Nevertheless, these extraction techniques are considered to be time-consuming and require a large amount of organic solvents. On this basis, microextraction techniques have been developed. Among them, liquid-phase microextraction has been standing out. This review describes the liquid-phase microextraction technique based on hollow fibers as a novel and promising alternative in sample preparation prior to chromatographic or electrophoretic analysis. The basic concepts related to this technique and its applicability in extraction of drugs are discussed.Keywords: liquid-phase microextraction; drug analysis; biological samples. INTRODUÇÃOAs técnicas de separação, tais como a cromatografia líquida de alta eficiência (HPLC), a cromatografia gasosa (GC) e a eletroforese capilar (CE), são perfeitamente adequadas para a análise de amostras contendo inúmeros componentes. No entanto, a determinação de analitos presentes em matrizes complexas, tais como plasma, soro, sangue total, homogenatos de tecidos, saliva ou urina, geralmente requer processos prévios de preparação das amostras bem elaborados. 1 Vários motivos justificam estes procedimentos, destacando-se a necessidade de eliminação prévia de parte dos componentes devido à complexidade das matrizes biológicas, a existência de proteínas que podem adsorver nas colunas cromatográficas ou nos capilares, além da necessidade de uma etapa de concentração das substâncias a serem analisadas, geralmente presentes em nível de traços. 1,2 As técnicas mais comumente utilizadas para extração e/ou pré-concentração de compostos presentes em fluidos biológicos são a extração líquido-líquido (LLE) e a extração em fase sólida (SPE). 3 Contudo, as tendências atuais apontam no sentido da utilização de menores quantidades de amostras, até mesmo para análises de traços; obtenção de maior seletividade e especificidade na extração; aumento no potencial para automação ou utilização de métodos "online", reduzindo assim a operação manual; desenvolvimento de métodos menos agressivos ao meio ambiente, com menor desperdí-cio e, o uso de quantidade mínima ou nenhuma de solventes orgâ-nicos. 4,5 Dentro deste contexto, técnicas de microextração que utilizam quantidades mínimas de solventes orgânicos e menos etapas na preparação das amostras vêm sendo desenvolvidas. Entre as principais técnicas de microextração existentes destacam-se a microextração em fase sólida (SPME), a microextração em gota suspensa (SDME) e a extração em membranas ["supported liquid membrane" (SLM), "microporous membrane liquid-liquid extraction" (MMLLE), "liquid-phase mi...

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“…10(b)] by an analogous mechanism to that by which basic drugs appear in stomach contents after intravenous injection. Even ion-pairing of polar analytes with trapping of ionized species in buffer (Ho et al, 2005) and electrokinetic migration (Pedersen-Bjergaard and have been demonstrated.…”

Section: Liquid-phase Micro-extractionmentioning

confidence: 99%

Micro‐extraction techniques in analytical toxicology: short review

Flanagan

Morgan

Spencer

et al. 2006

Biomedical Chromatography

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This paper discusses new developments in plasma micro-extraction techniques in the context of established micro-extraction and protein precipitation methodology. Simple liquid-liquid solvent extraction (LLE) of plasma with direct GC or HPLC analysis of the resulting extract has been used for many years. Butyl acetate and methyl t-butyl ether (MTBE) give efficient extraction of many drugs and metabolites from small volumes of plasma or whole blood at an appropriate pH, and form the upper layer, thus simplifying extract removal. Butyl acetate does not interfere with NPD, ECD or MS in GC, whilst MTBE has a relatively low UV cutoff (220 nm). Thus, HPLC eluents that use a high proportion of an organic component allow MTBE extracts to be analysed directly. 'Salting-out' and extractive derivatization using acetic anhydride or phenylboronic acid can be used with appropriate analytes. As regards protein precipitation, an important consideration is lowering the pH, although this is not feasible with acid-labile analytes. More recent developments include sold-phase micro-extraction (SPME) and liquid-phase micro-extraction (LPME). This latter technique especially may prove invaluable as analytes that cannot easily be extracted with LLE can be isolated simply at low cost with a minimum of apparatus.

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Liquid-phase microextraction based on carrier mediated transport combined with liquid chromatography–mass spectrometry

Cited by 88 publications

References 15 publications

Stereoselective determination of hydroxychloroquine and its metabolites in human urine by liquid‐phase microextraction and CE

Stereoselective determination of hydroxychloroquine and its metabolites in human urine by liquid‐phase microextraction and CE

Microextração em fase líquida (LPME): fundamentos da técnica e aplicações na análise de fármacos em fluidos biológicos

Micro‐extraction techniques in analytical toxicology: short review

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