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1.
Anal Bioanal Chem ; 413(14): 3717-3723, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33884461

RESUMO

In this work, hippuric acid (log P = 0.5), anthranilic acid (log P = 1.3), ketoprofen (log P = 3.6), and naproxen (log P = 3.0) were simultaneously extracted by a green microfluidic device based on the principles of liquid-phase microextraction (LPME). Different deep eutectic solvents (DESs) were investigated as supported liquid membrane (SLM), and a mixture of camphor and menthol as eutectic solvents in the molar ratio 1:1 was found to be highly efficient for the simultaneous extraction of non-polar and polar acidic drugs. LPME was conducted for 6 min per sample. Urine sample was delivered to the system at 1 µL min-1, and target analytes were extracted exhaustively (75-100% recovery) across the DES SLM, and into pure aqueous phosphate buffer pH 11.0 delivered as acceptor at 1 µL min-1. The acceptor was analyzed with liquid chromatography-UV detection. Interestingly, the DES enabled extraction of both the polar and non-polar model analytes at the same time; all chemicals were green and non-hazardous, and the chemical waste was less than 1 mg per sample.


Assuntos
Ácidos/isolamento & purificação , Ácidos/urina , Microextração em Fase Líquida/instrumentação , Adulto , Desenho de Equipamento , Feminino , Humanos , Dispositivos Lab-On-A-Chip , Solventes
2.
Anal Chem ; 90(17): 10417-10424, 2018 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-30092132

RESUMO

For the first time, a novel and versatile microfluidic device was developed to achieve the possibility of combining different extraction principles using a miniaturized approach for the extraction of different classes of analytes. This novel microchip is composed of a sandwich of three poly(methyl methacrylate) (PMMA) layers. Four channels allowed the combination of electromembrane extraction (EME) and liquid-phase microextraction (LPME) in three different ways: (I) EME and LPME, (II) EME and EME, or (III) LPME and LPME. The microchip can be used either (a) using a common acceptor phase (for both extractions) for the simultaneous extraction of drugs from different nature in a single step, or (b) a common sample solution (for both extractions) and two acceptor solutions for simultaneous drug separation. In this work, the performance of this novel microchip was demonstrated by simultaneous integration of EME and LPME using a common acceptor phase for both extractions. This configuration reduces the time of analysis allowing direct analysis in a single chip. The microchip was tested for extracting two different classes of analytes: five fluoroquinolones and four parabens as model analytes. All effective variables were optimized for EME and LPME. Under the optimized conditions, the reusable microchip enables simultaneous µ-EME/LPME with extraction efficiencies over 77% in only 8 min extraction and sample volume consumption lower than 40 µL. The optimized procedure was successfully applied to urine samples obtaining recoveries over 90% for all analytes.

3.
Anal Chim Acta ; 1274: 341572, 2023 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-37455082

RESUMO

In this work, a novel solvent-free microfluidic method based liquid phase microextraction has been proposed for the first time. A comprehensive study of liquid phase microextraction (LPME) and electromembrane extraction (EME) implemented in microfluidic formats has been carried out to investigate the efficiency of biodegradable membranes (such as agarose) without organic solvent to develop fully environmental microfluidic methods. For this study, non-polar and polar basic compounds (five) were selected as model analytes and different agarose membrane compositions were synthesized and tested with and without organic solvent (solvent-free). Under optimal experimental conditions, the extraction efficiencies obtained using solvent-free LPME-chip devices were similar to the ones obtained using solvent-free EME-chip devices at very low voltages (0.25 V), however, LPME microfluidic format was selected due to its simplicity. The proposed green microfluidic device was successfully applied in urine samples with recoveries between 80 and 93% for all analytes and relative standard deviation below 7% for all analytes. Results were compared with experiments previously conducted using conventional (polypropylene) membranes, observing that solvent-free microfluidic systems based on biodegradable solid support materials have proven to be an attractive alternative and offered the same advantages in terms of membrane stability allowing consecutive extractions compared to supported liquid membranes (SLM) microfluidic methods.


Assuntos
Microextração em Fase Líquida , Solventes , Microextração em Fase Líquida/métodos , Sefarose , Dispositivos Lab-On-A-Chip , Microfluídica , Membranas Artificiais
4.
Anal Chim Acta ; 1208: 339829, 2022 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-35525588

RESUMO

In sample preparation, simultaneous extraction of analytes of very different polarity from biological matrixes represents a challenge. In this work, verapamil hydrochloride (VRP), amitriptyline (AMP), tyramine (TYR), atenolol (ATN), metopropol (MTP) and nortriptyline (NRP) were used as basic model analytes and simultaneously extracted from urine samples by liquid-phase microextraction (LPME) in a microfluidic device. The model analytes (target compounds) were pharmaceuticals with 0.4 < log P < 5. Different organic solvents and mixtures of them were investigated as supported liquid membrane (SLM), and a mixture of 2:1 (v/v) tributyl phosphate (TBP) and dihexyl ether (DHE) was found to be highly efficient for the simultaneous extraction of the non-polar and polar model analytes. TBP reduced the intrinsic hydrophobicity of the SLM and facilitated extraction of polar analytes, while DHE served to minimize trapping of non-polar analytes. Sample and acceptor phase composition were adjusted to pH 12 and pH 1.5, respectively. Urine samples were pumped into the microfluidic system at 1 µL min-1 and the extraction was completed in 7 min. Recoveries exceeded 78% for the target analytes, and the relative standard deviation (n = 4) was below 7% in all cases. Using five microliters of SLM, the microfluidic extraction system showed good long-term stability, and the same SLM was used for more than 18 consecutive extractions.


Assuntos
Microextração em Fase Líquida , Microfluídica , Éteres , Humanos , Dispositivos Lab-On-A-Chip , Membranas Artificiais , Preparações Farmacêuticas , Solventes
5.
J Chromatogr A ; 1652: 462344, 2021 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-34186325

RESUMO

Liquid phase microextraction (LPME) into a microfluidic has undergone great advances focused on downscaled and miniaturized devices. In this work, a microfluidic device was developed for the extraction of sulfonamides in order to accelerate the mass transfer and passive diffusion of the analytes from the donor phase to the acceptor phase. The subsequent analysis was carried out by high performance liquid chromatography with UV-DAD (HPLC-DAD). Several parameters affecting the extraction efficiency of the method such as the supported liquid membrane, composition of donor and acceptor phase and flow rate were investigated and optimized. Tributyl phosphate was found to be a good supported liquid membrane which confers not only great affinity for analytes but also long-term stability, allowing more than 20 consecutive extractions without carry over effect. Under optimum conditions, extraction efficiencies were over 96 % for all sulfonamides after 10 minutes extraction and only 10 µL of sample was required. Relative standard deviation was between 3-5 % for all compounds. Method detection limits were 45, 57, 54 and 33 ng mL-1 for sulfadiazine (SDI), sulfamerazine (SMR), sulfamethazine (SMT) and sulfamethoxazole (SMX), respectively. Quantitation limits were 0.15, 0.19, 0.18 and 0.11 µg mL-1 for SDI, SMR, SMT SMX, respectively. The proposed microfluidic device was successfully applied for the determination of sulfonamides in urine samples with extraction efficiencies within the range of 86-106 %. The proposed method improves the procedures proposed to date for the determination of sulfonamides in terms of efficiency, reduction of the sample volume and extraction time.


Assuntos
Microextração em Fase Líquida , Microfluídica , Sulfonamidas , Urinálise , Cromatografia Líquida de Alta Pressão , Humanos , Dispositivos Lab-On-A-Chip , Sulfonamidas/análise , Sulfonamidas/isolamento & purificação , Urinálise/métodos
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