Solid-phase extraction, electrophoresis

D. Eigeys, A. Dua et and R. Aebersold, Identification of proteins by capillary electrophoresis-tandem mass specti ometiy . Evaluation of an on-line solid-phase extraction device , J. Chromatogr. A 763 295-306 (1997). 

Sun, X. et al., Capillary electrophoresis with amperometric detection of curcumin in Chinese herbal medicine pretreated by solid-phase extraction, J. Chromatogr. A, 962, 117, 2002. 

Carmine extracted from cochineal insects is one of the most used natural colorings for beverages and other foods. Some representative articles refer to isolation and spectrometric analysis or the use of HPLC or capillary electrophoresis (CE) to separate and characterize all cochineal pigments. Its active ingredient, carminic acid, was quantified by rapid HPLC-DAD or fluorescence spectrometry. Carminic acid, used as an additive in milk beverages, was separated within 9 min using a high-efficiency CE separation at pH 10.0 after a previous polyamide column solid phase extraction (SPE), ... 

Riu et al. [542] has reported the determination of linear ethyl benzane-sulfates in coastal waters using automated solid-phase extraction followed by capillary electrophoresis with ultraviolet detection, and confirmed by capillary electrophoresis-mass spectrometry. The detection limits were 1 pg/1 when 250 ml of coastal water was preconcentrated. 

Solid phase extraction (SPE) is fast and can work as a clean-up method when combined with capillary electrophoresis or used prior to HPLC/MS.34-37 Kerns et al.35 described an online alternating parallel SPE column with MS/MS detection and a turn-around time of 1.1 min. 

MOR were comparable (10 ng mL4), whereas those for DHC and EMOR were about fourfold lower. Furthermore, glucuronides were shown to react like the corresponding free opioids. Validation with real urine samples was performed with identification of the peaks by capillary electrophoresis-ion-trap mass spectrometry (CE-MS) after solid-phase extraction. 

R. Loos, M.C. Alonso and D. Barcelo, Solid-phase extraction of polar hydrophilic aromatic sulfonates followed by capillary zone electrophoresis-UV absorbance detection and ion-pair liquid chromatography-diode array UV detection and electrospray mass spectrometry. J. Chromatogr.A 890 (2000) 225-237. 

Hernandez, M., Borrull, R, and Calull, M. (2000). Determination of oxytetracycline and some impurities in plasma by non-aqueous capillary electrophoresis using solid-phase extraction. Chromatographia 52, 279—284. 

Solid phase extraction followed by capillary zone electrophoresis with UV absorbence detection has been shown to be applicable to the isolation and determination of 3,3 -dichlorobenzidine in water at ppm levels (Cavallaro et al. 1995). 

CZE = capillary zone electrophoresis EC = electrochemical detector GC = gas chromatography HCD = Hall conductivity detector HPLC = high performance liquid chromatography IDMS = isotope dilution mass spectrometry MS = mass spectrometry RSD = relative standard deviation SEE = supercritical fluid extraction SPE = solid phase extraction UV = ultraviolet absorbance detection... 

Jenkins et al. developed a capillary electrophoresis system for the measurement of iohexol as a marker of the glomerular filtration rate (GFR) with a run time of 5.25 min and a coefficient of variation (CV) of 4.3% at 80 mg L" [121]. The GFR, calculated from the plasma clearance, had a reproducibility of 5.47 %. A similar approach (liquid chromatography-mass spectrometry with positive electrospray ionization after enrichment by solid phase extraction) was applied by Putschew et al. for the determination of iodinated contrast agents in treatment plant effluents and surface waters [118]. 

Lu, Q., G. E. Collins, M. Smith, and J. Wang. Sensitive capillary electrophoresis microchip determination of trinitroaromatic explosives in nonaqueous electrolyte following solid phase extraction. Anal. Chim. Acta 469, 253-260 (2002). 

Benavente, R, Vescina, M. C., Hernandez, E., Sanz-Nebot, V., Barbosa, J., and Guzman, N. A., Lowering the concentration limits of detection by on-line solid-phase extraction-capillary electrophoresis-electrospray mass spectrometry. Journal of Chromatography A 1140(1-2), 205-212, 2007. 

Up to now, most efforts have been directed towards the preparation of uniformly sized spherical MIP particles in the micrometre range. This is the obvious consequence of the need for this kind of materials as fillers for high-performance chromatographic columns, capillaries for electrophoresis, cartridges for solid-phase extractions and other applications requiring selective stationary phases. Additionally though, strategies for the preparation of other more sophisticated MIP forms, such as membranes, (nano)monoliths, films, micro- and nanostructured surfaces etc. 

Recently, a method for preparing MIP monolithic columns for electrophoresis, chromatography and solid-phase extraction has been developed, which uses a preformed polymeric monolith, onto which an MIP with specific recognition sites is subsequently grafted [149, 179-181]. 

Electropherograms of a urine sample (8 ml) spiked with non-steroidal anti-inflammatory drugs (10 (Jig/ml each) after direct CE analysis (b) and at-line SPE-CE (c). Peak identification is as follows I, ibuprofen N, naproxen K, ketoprofen F, flurbiprofen. Reprinted from Journal of Chromatography, B 719, J. R. Veraart et al., At-line solid-phase extraction for capillary electrophoresis application to negatively charged solutes, pp. 199-208, copyright 1998, with permission from Elsevier Science. 

J. R. Veraart, C. Gooijer, H. Lingeman, N. H. Velthorst and U. A. Th Brinkman, At-line solid-phase extraction coupled to capillary electrophoresis determination of amphoteric compounds in biological samples , 7. High Resolut. Chromatogr. 22 183-187(1999). 

Notes LOD, limit of detection MeOH, methanol EtOH, ethanol ACN, acetonitrile EtAC, ethyl acetate SPE, solid phase extraction HLB (hydrophilic lipophilic balanced) TFA, trifluoroacetic acid GC, gas chromatography TMS, trimethylsilyl MS, mass spectrometry HPLC, high-performance liquid chromatography DAD, diode array detector NMR, nuclear magnetic resonance ESI, electrospray ionization APCI, atmospheric pressure chemical ionization CE, capillary electrophoresis ECD, electrochemical detector CD, conductivity detector TLC, thin layer chromatography PDA, photodiode array detector. 

Capillary electrophoresis (CE) coupled to MS has the advantage of high resolution and soft ionization for biomolecules, which may be used to differentiate post-translational modifications and variants of intact proteins and oligonucleotides. Different modes of CE (capillary zone electrophoresis, capillary isoelectric focusing, capillary electrochromatography, micellar electrokinetic chromatography, nonaqueous capillary electrophoresis) to MS as well as online preconcentration techniques (transient capillary isotachophoresis, solid-phase extraction, membrane preconcentration) are used to compensate for the restricted detection sensitivity of the CE methodology [77, 78]. 

DNA purification Solvent extraction and precipitation, gel electrophoresis, chromatography size exclusion, ion exchange, solid-phase extraction, SPRI, affinity purification... 

Jemere, A.B., Oleschuk, R.D., Ouchen, F., Fajuyigbe, F., Harrison, D.J., An integrated solid-phase extraction system for sub-picomolar detection. Electrophoresis... 

Wolfe, K.A., Breadmore, M.C., Ferrance, J.P., Power, M.E., Conroy, J.F., Norris, P.M., Landers, J.P., Toward a microchip-based solid-phase extraction method for isolation of nucleic acids. Electrophoresis 2001, 23, 727-733. 

Arraez-Roman, D., GomezCaravaca, A. M., Gomez-Romero, M., Segura-Carratero, A., and Fernandez-Gutierrez, A. (2006). Identification of phenolic compounds in rosemary honey using solid-phase extraction by capillary electrophoresis-electrospray ionization mass spectrometry. ]. Pharm. Biomed. Anal. 41,1648-1656. 

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