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Abstract
This chapter provides a guide for microfluidic devices development and optimization focused on chemical analysis applications, which includes medicine, biology, chemistry, and environmental monitoring, showing high-level performance associated with a specific functionality. Examples are chemical analysis, solid phase extraction, chromatography, immunoassay analysis, protein and DNA separation, cell sorting and manipulation, cellular biology, and mass spectrometry. In this chapter, most information is related to microfluidic devices design and fabrication used to perform several steps concerning chemical analysis, process preparation of reagents, samples reaction and detection, regarding water quality monitoring. These steps are especially relevant to lab-on-chip (LOC) and micro-total-analysis-systems (μTAS). μTAS devices are developed in order to simplify analytical chemist work, incorporating several analytical procedures into flow systems. In the case of miniaturized devices, the analysis time is reduced, and small volumes (nL) can be used.
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Ahmed HM, Ebeid WB. The use of laser-induced fluorescence or ultraviolet detectors for sensitive and selective analysis of tobramycin or erythropoietin in complex samples. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2015; 143:12-19. [PMID: 25706680 DOI: 10.1016/j.saa.2015.02.025] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Revised: 01/29/2015] [Accepted: 02/04/2015] [Indexed: 06/04/2023]
Abstract
Complex samples analysis is a challenge in pharmaceutical and biopharmaceutical analysis. In this work, tobramycin (TOB) analysis in human urine samples and recombinant human erythropoietin (rhEPO) analysis in the presence of similar protein were selected as representative examples of such samples analysis. Assays of TOB in urine samples are difficult because of poor detectability. Therefore laser induced fluorescence detector (LIF) was combined with a separation technique, micellar electrokinetic chromatography (MEKC), to determine TOB through derivatization with fluorescein isothiocyanate (FITC). Borate was used as background electrolyte (BGE) with negative-charged mixed micelles as additive. The method was successively applied to urine samples. The LOD and LOQ for Tobramycin in urine were 90 and 200ng/ml respectively and recovery was >98% (n=5). All urine samples were analyzed by direct injection without sample pre-treatment. Another use of hyphenated analytical technique, capillary zone electrophoresis (CZE) connected to ultraviolet (UV) detector was also used for sensitive analysis of rhEPO at low levels (2000IU) in the presence of large amount of human serum albumin (HSA). Analysis of rhEPO was achieved by the use of the electrokinetic injection (EI) with discontinuous buffers. Phosphate buffer was used as BGE with metal ions as additive. The proposed method can be used for the estimation of large number of quality control rhEPO samples in a short period.
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Affiliation(s)
- Hytham M Ahmed
- Pharmaceutical Analysis Department, Faculty of Pharmacy, Damanhour University, Damanhour, Egypt.
| | - Wael B Ebeid
- SEDICO Pharmaceuticals, Merck & Co External Partner, 6th of October City, Cairo, Egypt
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Sun Y, Li Y, Zeng J, Lu Q, Li PCH. Microchip electrophoretic separation and fluorescence detection of chelerythrine and sanguinarine in medicinal plants. Talanta 2015; 142:90-6. [PMID: 26003696 DOI: 10.1016/j.talanta.2015.04.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2014] [Revised: 03/29/2015] [Accepted: 04/02/2015] [Indexed: 12/17/2022]
Abstract
A new method has been developed for separation of chelerythrine and sanguinarine in medicinal plants used in traditional Chinese medicine (TCM). The separation is achieved by microchip electrophoresis (CE) using laser-induced fluorescence detection. The CE separation is achieved by using a hydro-organic medium as the electrolyte buffer. The experimental results are consistent with the prediction by theory in terms of resolution and migration speed because of the low Joule heat generated in microchip CE. In addition, formamide was found to have a potential for separation of molecules with similar chemical structures. Based on these findings, a run buffer containing 50% formamide was used to separate chelerythrine (CHE) and sanguinarine (SAN). The influencing factors, such as solvent of run buffer, pH of buffer, separation distance, and separation voltage, were optimized. Baseline separation of chelerythrine and sanguinarine was achieved within 120 s under an electrical voltage of 1.8 kV. Good linearity was observed in the concentration range of 0.15-550 μg mL(-1) (r=0.9993) for CHE and in the range of 0.3-600 μg mL(-1) (r=0.9998) for SAN. A low limit of detection (LOD) was achieved because of the high sensitivity achieved by laser-induced fluorescence detection (i.e. 5.0 ng mL(-1) and 2.0 ng mL(-1) for CHE and SAN, respectively). The contents of CHE are found to be 641.8±7.5 and 134.0±2.3 mg/kg in extracts of Macleaya cordata and Chelidonium majus, respectively, with good recovery of above 99%. The corresponding values for SAN found in these Chinese herbal extracts are 681.8±7.9 mg/kg and 890.5±8.9 mg/kg, respectively.
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Affiliation(s)
- Yue Sun
- School of Traditional Chinese Medicine, Guangdong Pharmaceutical University, Guangzhou 510006, China; Key Laboratory of State Administration of TCM for Digital Quality Evaluation of Chinese Materia Medica, Guangzhou 510006, China; Engineering & Technology Research Center for Chinese Materia Medica Quality of the Universities of Guangdong Province, Guangzhou 510006, China.
| | - Yuanyuan Li
- School of Traditional Chinese Medicine, Guangdong Pharmaceutical University, Guangzhou 510006, China
| | - Jiajian Zeng
- School of Traditional Chinese Medicine, Guangdong Pharmaceutical University, Guangzhou 510006, China
| | - Qixian Lu
- School of Traditional Chinese Medicine, Guangdong Pharmaceutical University, Guangzhou 510006, China
| | - Paul C H Li
- Department of Chemistry, Simon Fraser University, Burnaby, BC, Canada V5A 1S6.
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Feliciano RP, Heintz JA, Krueger CG, Vestling MM, Reed JD. Fluorescent labeling of cranberry proanthocyanidins with 5-([4,6-dichlorotriazin-2-yl]amino)fluorescein (DTAF). Food Chem 2014; 166:337-345. [PMID: 25053065 DOI: 10.1016/j.foodchem.2014.06.031] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Revised: 06/05/2014] [Accepted: 06/06/2014] [Indexed: 10/25/2022]
Abstract
A novel methodology was developed to elucidate proanthocyanidins (PAC) interaction with extra-intestinal pathogenic Escherichia coli (ExPEC). PAC inhibit ExPEC invasion of epithelial cells and, therefore, may prevent transient gut colonization, conferring protection against subsequent extra-intestinal infections, such as urinary tract infections. Until now PAC have not been chemically labeled with fluorophores. In this work, cranberry PAC were labeled with 5-([4,6-dichlorotriazin-2-yl]amino) fluorescein (DTAF), detected by high-performance liquid chromatography with diode-array detection and characterized by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). We report single and double fluorescent-labeled PAC with one or two chlorine atoms displaced from DTAF in alkaline pH via nucleophilic substitution. Fluorescent labeling was confirmed by fragmentation experiments using MALDI-TOF/TOF MS. Fluorescent labeled PAC were able to promote ExPEC agglutination when observed with fluorescence microscopy. DTAF tagged PAC may be used to trace the fate of PAC after they agglutinate ExPEC and follow PAC-ExPEC complexes in cell culture assays.
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Affiliation(s)
- Rodrigo P Feliciano
- University of Wisconsin-Madison, Dept. of Food Science, 1605 Linden Drive, Madison, WI 53706, USA; University of Wisconsin-Madison, Reed Research Group, Dept. Animal Sciences, 1675 Observatory Drive, Madison, WI 53706, USA
| | - Joseph A Heintz
- Biological & Biomaterials Preparation, Imaging & Characterization Facility, Dept. Animal Sciences, 1675 Observatory Drive, Madison, WI 53706, USA
| | - Christian G Krueger
- University of Wisconsin-Madison, Reed Research Group, Dept. Animal Sciences, 1675 Observatory Drive, Madison, WI 53706, USA; Complete Phytochemical Solutions, LLC, 317 South Street, Cambridge, WI 53523, USA
| | - Martha M Vestling
- University of Wisconsin-Madison, Dept. of Chemistry, 1101 University Ave., Madison, WI 53706, USA
| | - Jess D Reed
- University of Wisconsin-Madison, Reed Research Group, Dept. Animal Sciences, 1675 Observatory Drive, Madison, WI 53706, USA; Complete Phytochemical Solutions, LLC, 317 South Street, Cambridge, WI 53523, USA.
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Chhina SK. . J Med Biol Eng 2011; 31:105. [DOI: 10.5405/jmbe.838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Zhang X, Liu J, Qiao H, Ni J, Shi Y. Determination and Pharmacokinetics of Isoliquiritigenin in Rat Plasma by RP–LC After Intravenous Administration. Chromatographia 2009. [DOI: 10.1365/s10337-009-1236-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Blas M, Delaunay N, Rocca JL. Electrokinetic-based injection modes for separative microsystems. Electrophoresis 2008; 29:20-32. [DOI: 10.1002/elps.200700389] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Kuswandi B, Nuriman, Huskens J, Verboom W. Optical sensing systems for microfluidic devices: A review. Anal Chim Acta 2007; 601:141-55. [PMID: 17920386 DOI: 10.1016/j.aca.2007.08.046] [Citation(s) in RCA: 241] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2007] [Revised: 08/22/2007] [Accepted: 08/23/2007] [Indexed: 10/22/2022]
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Shi B, Huang W, Cheng J. Determination of neurotransmitters in PC 12 cells by microchip electrophoresis with fluorescence detection. Electrophoresis 2007; 28:1595-600. [PMID: 17447240 DOI: 10.1002/elps.200600615] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
A sensitive fluorescence detection system with an Hg-lamp as the excitation source and a photon counter as the detector for microchip CE (MCE) has been developed. O-Phthaldialdehyde (OPA, lambda(ex) = 340 nm) was employed to label the catecholamine neurotransmitters such as dopamine (DA), norepinephrine (NE), and amino acid neurotransmitters including alanine (Ala), taurine (Tau), glycine (Gly), glutamic acid (Glu), and aspartic acid (Asp). The separation of seven derivatized neurotransmitters was successfully performed in MCE and the detection limits (S/N = 3) for DA, NE, Ala, Tau, Gly, Glu, and Asp were 0.85, 0.49, 0.23, 0.15, 0.13, 0.18, and 0.29 fmol, respectively. The system was then successfully applied for separation and determination of neurotransmitters in rat pheochromocytoma (PC 12) cells, and the average amounts of analyte per cell from a cell population were 2.5 fmol for DA, 3.3 fmol for Ala, 8.2 fmol for Tau, 4.0 fmol for Gly, and 1.9 fmol for Glu, respectively. By single-cell injection mode, electrophoresis separation and quantitative measurement of Glu in individual PC 12 cells was obtained. The average value of Glu per cell from single PC 12 cells analysis was found to be 3.5 +/- 3.1 fmol.
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Affiliation(s)
- Baoxian Shi
- College of Chemistry and Molecular Science Wuhan University, Wuhan, PR China
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Götz S, Karst U. Recent developments in optical detection methods for microchip separations. Anal Bioanal Chem 2007; 387:183-92. [PMID: 17031620 PMCID: PMC7080113 DOI: 10.1007/s00216-006-0820-8] [Citation(s) in RCA: 124] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2006] [Revised: 08/18/2006] [Accepted: 08/31/2006] [Indexed: 10/26/2022]
Abstract
This paper summarizes the features and performances of optical detection systems currently applied in order to monitor separations on microchip devices. Fluorescence detection, which delivers very high sensitivity and selectivity, is still the most widely applied method of detection. Instruments utilizing laser-induced fluorescence (LIF) and lamp-based fluorescence along with recent applications of light-emitting diodes (LED) as excitation sources are also covered in this paper. Since chemiluminescence detection can be achieved using extremely simple devices which no longer require light sources and optical components for focusing and collimation, interesting approaches based on this technique are presented, too. Although UV/vis absorbance is a detection method that is commonly used in standard desktop electrophoresis and liquid chromatography instruments, it has not yet reached the same level of popularity for microchip applications. Current applications of UV/vis absorbance detection to microchip separations and innovative approaches that increase sensitivity are described. This article, which contains 85 references, focuses on developments and applications published within the last three years, points out exciting new approaches, and provides future perspectives on this field.
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Affiliation(s)
- Sebastian Götz
- Chemical Analysis Group and MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - Uwe Karst
- Chemical Analysis Group and MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
- Present Address: Institute of Inorganic and Analytical Chemistry, University of Münster, Corrensstr. 30, 48149 Münster, Germany
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Wang W, Li C, Li Y, Hu Z, Chen X. Rapid and ultrasensitive determination of ephedrine and pseudoephedrine derivatizated with 5-(4,6-dichloro-s-triazin-2-ylamino) fluorescein by micellar electrokinetic chromatography with laser-induced fluorescence detection. J Chromatogr A 2006; 1102:273-9. [PMID: 16297394 DOI: 10.1016/j.chroma.2005.10.015] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2005] [Revised: 09/20/2005] [Accepted: 10/11/2005] [Indexed: 11/22/2022]
Abstract
This paper presents a micellar electrokinetic chromatography method with laser-induced fluorescence detection to analyze ephedrine (E) and pseudoephedrine (PE) after derivatizated with 5-(4,6-dichloro-s-triazin-2-ylamino) fluorescein. The optimum derivatization conditions were: 0.05 M Na2CO(3/NaHCO3 (pH 9.5), reaction time 30 min at 45 degrees C, molar ratio of DTAF to E and PE mixture 20:1. The baseline separation was achieved within 8 min with running buffer composed of 20 mM borate+20 mM SDS+15% acetonitrile (v/v) (adjusted pH 9.8), and applied voltage of 20 kV. Good linearity relationships (correlation coefficients: 0.9906 for E and 0.9941 for PE) between the peak heights and concentration of the analytes were obtained (2.5-50 ngmL(-1)). The detection limits for E and PE were 3.85 x 10(-4) and 1.41 x 10(-4)ngmL(-1), respectively, which indicated that the proposed method surpassed other chromatographic alternatives in terms of limit of detection by at least 10(3) folds. The method was applied to the analysis of the two alkaloids in ephedra herb plants and its preparations with recoveries in the range of 89.6-107.0%.
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Affiliation(s)
- Weiping Wang
- Department of Chemistry, Lanzhou University, Lanzhou 730000, PR China
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Orejuela E, Silva M. Rapid determination of aniline metabolites of chlorpropham in potatoes by micellar electrokinetic chromatography using negative-charged mixed micelles and laser-induced fluorescence detection. Electrophoresis 2005; 26:2991-8. [PMID: 15995980 DOI: 10.1002/elps.200410330] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A rapid, reliable method has been developed for the multi-residue analysis of aniline metabolites of chlorpropham in potato samples. The method involves the precolumn derivatization of aniline metabolites with 5-(4,6-dichloro-s-triazin-2-ylamino) fluorescein (DTAF) and their subsequent separation and determination by micellar electrokinetic capillary chromatography with laser-induced fluorescence detection (MEKC-LIF). The optimum procedure includes a derivatization step of the aniline metabolites (3-chloroaniline, 3-chloro-4-hydroxyaniline and 3-chloro-4-methoxyaniline) at 40 degrees C for 40 min and a 5-fold dilution prior to MEKC analysis, which is conducted within about 7 min using negative-charged mixed micelles (SDS/Triton X-100) in the running buffer. Under these conditions, the DTAF-anilines were readily detected at 0.3-3.1 microg/L level with a precision of 4.8-6.4%. These results indicate that negative-charged mixed surfactant MEKC-LIF is useful as a selective, rapid, and sensitive tool for the determination of these anilines and surpasses other electrophoretic alternatives based on the use of fluorescein-isothiocyanate (FITC) as label reagent. Finally, the potato matrix showed no significant effects on the derivatization and determination of these analytes, since the analytical figures of merit for the real samples were similar to those obtained in aqueous solutions, and the average recovery at fortification levels of 10-250 microg/kg was over 97%.
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Affiliation(s)
- Eva Orejuela
- Department of Analytical Chemistry, Marie-Curie Building (Annex), Rabanales Campus, University of Cordoba, Spain
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