175 research outputs found

    Selective and sensitive chemiluminescence determination of MCPB: flow injection and liquid chromatography

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    This paper was published in Applied Spectroscopy and is made available as an electronic reprint with the permission of OSA. The paper can be found at the following URL on the OSA website: http://dx.doi.org/10.1177/0003702815620133 . Systematic or multiple reproduction or distribution to multiple locations via electronic or other means is prohibited and is subject to penalties under law.Two new chemiluminescence (CL) methods are described for the determination of the herbicide 4-(4-chloro-o-tolyloxy) butyric acid (MCPB). First, a flow injection chemiluminescence (FI-CL) method is proposed. In this method, MCPB is photodegraded with an ultraviolet (UV) lamp and the photoproducts formed provide a great CL signal when they react with ferricyanide in basic medium. Second, a high-performance liquid chromatography chemiluminescence (HPLC-CL) method is proposed. In this method, before the photodegradation and CL reaction, the MCPB and other phenoxyacid herbicides are separated in a C18 column. The experimental conditions for the FI-CL and HPLC-CL methods are optimized. Both methods present good sensitivity, the detection limits being 0.12 mg L 1 and 0.1 mg L 1 (for FI-CL and HPLC-CL, respectively) when solid phase extraction (SPE) is applied. Intra- and interday relative standard deviations are below 9.9%. The methods have been satisfactorily applied to the analysis of natural water samples. FI-CL method can be employed for the determination of MCPB in simple water samples and for the screening of complex water samples in a fast, economic, and simple way. The HPLC-CL method is more selective, and allows samples that have not been resolved with the FI-CL method to be solved.Meseguer-Lloret, S.; Torres-Cartas, S.; Catalá-Icardo, M.; Gómez Benito, C. (2016). Selective and sensitive chemiluminescence determination of MCPB: flow injection and liquid chromatography. Applied Spectroscopy. 70(2):312-321. doi:10.1177/0003702815620133S312321702Moral, A., Caballo, C., Sicilia, M. D., & Rubio, S. (2012). Highly efficient microextraction of chlorophenoxy acid herbicides in natural waters using a decanoic acid-based nanostructured solvent prior to their quantitation by liquid chromatography–mass spectrometry. Analytica Chimica Acta, 709, 59-65. doi:10.1016/j.aca.2011.10.016Herrero-Hernández, E., Rodríguez-Gonzalo, E., Andrades, M. S., Sánchez-González, S., & Carabias-Martínez, R. (2013). Occurrence of phenols and phenoxyacid herbicides in environmental waters using an imprinted polymer as a selective sorbent. Science of The Total Environment, 454-455, 299-306. doi:10.1016/j.scitotenv.2013.03.029Baggiani, C., Giovannoli, C., Anfossi, L., & Tozzi, C. (2001). Molecularly imprinted solid-phase extraction sorbent for the clean-up of chlorinated phenoxyacids from aqueous samples. Journal of Chromatography A, 938(1-2), 35-44. doi:10.1016/s0021-9673(01)01126-8Wintersteiger, R., Goger, B., & Krautgartner, H. (1999). Quantitation of chlorophenoxy acid herbicides by high-performance liquid chromatography with coulometric detection. Journal of Chromatography A, 846(1-2), 349-357. doi:10.1016/s0021-9673(99)00429-xPeruzzi, M., Bartolucci, G., & Cioni, F. (2000). Determination of phenoxyalkanoic acids and other herbicides at the ng/ml level in water by solid-phase extraction with poly(divinylbenzene-co-N-vinylpyrrolidone) sorbent and high-performance liquid chromatography–diode-array detection. Journal of Chromatography A, 867(1-2), 169-175. doi:10.1016/s0021-9673(99)01141-3Ranz, A., & Lankmayr, E. (2006). Screening and optimization of the derivatization of polar herbicides with trimethylanilinium hydroxide for GC-MS analysis. Journal of Biochemical and Biophysical Methods, 69(1-2), 3-14. doi:10.1016/j.jbbm.2006.02.007Nuhu, A. A., Basheer, C., Alhooshani, K., & Al-Arfaj, A. R. (2012). Determination of phenoxy herbicides in water samples using phase transfer microextraction with simultaneous derivatization followed by GC-MS analysis. Journal of Separation Science, 35(23), 3381-3388. doi:10.1002/jssc.201200218Jiménez, J. J. (2013). Simultaneous liquid–liquid extraction and dispersive solid-phase extraction as a sample preparation method to determine acidic contaminants in river water by gas chromatography/mass spectrometry. Talanta, 116, 678-687. doi:10.1016/j.talanta.2013.07.052EREMIN, S., LAASSIS, B., & AARON, J. (1996). Photochemical-fluorimetric method for the determination of total chlorophenoxyacid herbicides. Talanta, 43(3), 295-301. doi:10.1016/0039-9140(95)01751-8Jafari, M. T., Saraji, M., & Yousefi, S. (2012). Negative electrospray ionization ion mobility spectrometry combined with microextraction in packed syringe for direct analysis of phenoxyacid herbicides in environmental waters. Journal of Chromatography A, 1249, 41-47. doi:10.1016/j.chroma.2012.06.024Tsogas, G. Z., Giokas, D. L., Nikolakopoulos, P. G., Vlessidis, A. G., & Evmiridis, N. P. (2006). Determination of the pesticide carbaryl and its photodegradation kinetics in natural waters by flow injection–direct chemiluminescence detection. Analytica Chimica Acta, 573-574, 354-359. doi:10.1016/j.aca.2005.11.058Albert-García, J. R., & Calatayud, J. M. (2008). Determination of the herbicide benfuresate by its photo-induced chemiluminescence using flow multicommutation methodology. Talanta, 75(3), 717-724. doi:10.1016/j.talanta.2007.12.003Catalá-Icardo, M., López-Paz, J. L., Choves-Barón, C., & Peña-Bádena, A. (2012). Native vs photoinduced chemiluminescence in dimethoate determination. Analytica Chimica Acta, 710, 81-87. doi:10.1016/j.aca.2011.10.043Gómez-Benito, C., Meseguer-Lloret, S., & Torres-Cartas, S. (2013). Sensitive determination of Fenamiphos in water samples by flow injection photoinduced chemiluminescence. International Journal of Environmental Analytical Chemistry, 93(2), 152-165. doi:10.1080/03067319.2012.663755Beale, D. J., Porter, N. A., & Roddick, F. A. (2009). A fast screening method for the presence of atrazine and other triazines in water using flow injection with chemiluminescent detection. Talanta, 78(2), 342-347. doi:10.1016/j.talanta.2008.11.033Catalá-Icardo, M., López-Paz, J. L., & Pérez-Plancha, L. M. (2014). Fast Determination of Thiacloprid by Photoinduced Chemiluminescence. Applied Spectroscopy, 68(6), 642-648. doi:10.1366/13-07330Torres-Cartas, S., Gómez-Benito, C., & Meseguer-Lloret, S. (2011). FI on-line chemiluminescence reaction for determination of MCPA in water samples. Analytical and Bioanalytical Chemistry, 402(3), 1289-1296. doi:10.1007/s00216-011-5567-1Catalá-Icardo, M., Lahuerta-Zamora, L., Torres-Cartas, S., & Meseguer-Lloret, S. (2014). Determination of organothiophosphorus pesticides in water by liquid chromatography and post-column chemiluminescence with cerium(IV). Journal of Chromatography A, 1341, 31-40. doi:10.1016/j.chroma.2014.03.024Huertas-Pérez, J. F., & García-Campaña, A. M. (2008). Determination of N-methylcarbamate pesticides in water and vegetable samples by HPLC with post-column chemiluminescence detection using the luminol reaction. Analytica Chimica Acta, 630(2), 194-204. doi:10.1016/j.aca.2008.09.047Orejuela, E., & Silva, M. (2003). Monitoring some phenoxyl-type N-methylcarbamate pesticide residues in fruit juices using high-performance liquid chromatography with peroxyoxalate-chemiluminescence detection. Journal of Chromatography A, 1007(1-2), 197-201. doi:10.1016/s0021-9673(03)00934-8GALERA, M., GARCIA, M., & VALVERDE, R. (2008). Determination of photoirradiated high polar benzoylureas in tomato by HPLC with luminol chemiluminescence detection. Talanta, 76(4), 815-823. doi:10.1016/j.talanta.2008.04.052Rosales-Conrado, N., León-González, M. E., Pérez-Arribas, L. V., & Polo-Díez, L. M. (2005). Effect of temperature on the separation of chlorophenoxy acids and carbamates by capillary high-performance liquid chromatography and UV (or diode array) detection. Journal of Chromatography A, 1081(1), 114-121. doi:10.1016/j.chroma.2004.12.083Geerdink, R. B., van Tol-Wildenburg, S., Niessen, W. M. A., & Brinkman, U. A. T. (1997). Determination of Phenoxy Acid Herbicides From Aqueous Samples by Improved Clean-up on Polymeric Pre-columns at High pH. The Analyst, 122(9), 889-894. doi:10.1039/a702338

    Determination of organothiophosphorus pesticides in water by liquid chromatography and post-column chemiluminescence with cerium(IV)

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    A new, fast, selective and sensitive method has been developed for the simultaneous determination of nine organothiophosphorus (OTP) pesticides, namely omethoate, dimethoate, disulfoton-sulfoxide, methidathion, phosmet, malathion, diazinon, pirimiphos-methyl and chlorpyrifos. The pesticides were separated on a Kinetex C18 column by gradient elution with acetonitrile:water. A post-column basic hydrolysis of the pesticides and later a chemiluminescence (CL) reaction with cerium (IV) in acid medium was carried out. Hexadecylpyridinium chloride highly enhanced the CL emission. Under optimized conditions, linearity, precision, limits of detection and quantification, and accuracy were determined. Both selectivity and sensitivity were compared with those obtained with UV detection. In combination with SPE, limits of detection in the range 15-80 ng/L and 5-30 ng/L were obtained when 250 mL and 1000 mL of solution were treated, respectively. When applied to 250 mL of sample the inter-day precision of the method was between 3.5% and 7.3% and the intra-day precision between 2.9% and 6.0%. The method was applied to determine OTP pesticides in spiked water samples from different origins: irrigation, river, sea, ground, spring, mineral and tap waters, being the percentage of recovery of added amounts near 100% form most of the pesticides.Catalá Icardo, M.; Lahuerta Zamora, L.; Torres-Cartas, S.; Meseguer-Lloret, S. (2014). Determination of organothiophosphorus pesticides in water by liquid chromatography and post-column chemiluminescence with cerium(IV). Journal of Chromatography A. 1341:31-40. doi:10.1016/j.chroma.2014.03.0243140134

    A proposed mechanism for nitrogen acquisition by grass seedlings through oxidation of symbiotic bacteria

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    In this paper we propose and provide evidence for a mechanism, oxidative nitrogen scavenging (ONS), whereby seedlings of some grass species may extract nitrogen from symbiotic diazotrophic bacteria through oxidation by plant-secreted reactive oxygen species (ROS). Experiments on this proposed mechanism employ tall fescue (Festuca arundinaceae) seedlings to elucidate features of the oxidative mechanism. We employed 15N2 gas assimilation experiments to demonstrate nitrogen fixation, direct microscopic visualization of bacteria on seedling surfaces to visualize the bacterial oxidation process, reactive oxygen probes to test for the presence of H2O2 and cultural experiments to assess conditions under which H2O2 is secreted by seedlings. We also made surveys of the seedlings of several grass species to assess the distribution of the phenomenon of microbial oxidation in the Poaceae. Key elements of the proposed mechanism for nitrogen acquisition in seedlings include: 1) diazotrophic bacteria are vectored on or within seeds; 2) at seed germination bacteria colonize seedling roots and shoots; 3) seedling tissues secrete ROS onto bacteria; 4) bacterial cell walls, membranes, nucleic acids, proteins and other biological molecules are oxidized; 5) nitrates and/or smaller fragments of organic nitrogen-containing molecules resulting from oxidation may be absorbed by seedling tissues and larger peptide fragments may be further processed by secreted or cell wall plant proteases until they are small enough for transport into cells. Hydrogen peroxide secretion from seedling roots and bacterial oxidation was observed in several species in subfamily Pooideae where seeds possessed adherent paleas and lemmas, but was not seen in grasses that lacked this feature or long-cultivated crop species

    Photografted fluoropolymers as novel chromatographic supports for polymeric monolithic stationary phases

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    [EN] In this study, porous polymer monoliths were in situ synthesized in fluoropolymers tubing to prepare microbore HPLC columns. To ensure the formation of robust homogeneous polymer monoliths in these housing supports, the inner surface of fluoropolymer tubing was modified in a two-step photografting process. Raman spectroscopy and scanning electron microscopy (SEM) confirmed the successful modification of the inner poly(ethylene-co-tetrafluoroethylene) (ETFE) wall and the subsequent attachment of a monolith onto the wall. Poly(glycidyl methacrylate-co-divinylbenzene), poly(butyl methacrylate-co-ethyleneglycol dimethacrylate) and poly(styrene-co-divinylbenzene) monoliths were in situ synthesized by thermal polymerization within the confines of surface vinylized ETFE tubes. The resulting monoliths exhibited good permeability and mechanical stability (pressure resistance up to 9¿MPa). The chromatographic performance of these different monolithic columns was evaluated via the separation of alkyl benzenes and proteins in a conventional HPLC system.This work was supported by project PROMETEO/2016/145 (Conselleria d'Educacio, Investigacio, Cultura i Esport,Esport, Generalitat Valenciana, Spain). The authors also thank Dr. S. Laredo-Ortiz from the Atomic Spectroscopy section of the SCSIE (University of Valencia), for her help in Raman measurements.Catalá-Icardo, M.; Torres-Cartas, S.; Meseguer-Lloret, S.; Simó-Alfonso, E.; Herrero Martínez, J. (2018). Photografted fluoropolymers as novel chromatographic supports for polymeric monolithic stationary phases. Talanta. 187:216-222. doi:10.1016/j.talanta.2018.05.026S21622218

    Recent Advances in Molecularly Imprinted Membranes for Sample Treatment and Separation

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    [EN] This review describes the recent advances from the past five years concerning the development and applications of molecularly imprinted membranes (MIMs) in the field of sample treatment and separation processes. After a short introduction, where the importance of these materials is highlighted, a description of key aspects of membrane separation followed by the strategies of preparation of these materials is described. The review continues with several analytical applications of these MIMs for sample preparation as well as for separation purposes covering pharmaceutical, food, and environmental areas. Finally, a discussion focused on possible future directions of these materials in extraction and separation field is also given.This work was supported by project RTI2018-095536-B-I00 (Ministry of Science, Innovation and Universities, Spain).Torres-Cartas, S.; Catalá-Icardo, M.; Meseguer-Lloret, S.; Simó-Alfonso, EF.; Herrero-Martínez, JM. (2020). Recent Advances in Molecularly Imprinted Membranes for Sample Treatment and Separation. Separations. 7(4):1-28. https://doi.org/10.3390/separations7040069S1287

    Extraction and preconcentration of organophosphorus pesticides in water by using a polymethacrylate-based sorbent modified with magnetic nanoparticles

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    [EN] A polymethacrylate-based sorbent modified with magnetic nanoparticles (MNPs) has been synthesized and used as sorbent for solid-phase extraction (SPE) and magnetic solid-phase extraction (MSPE) of three organophosphorus pesticides (phosmet, pirimiphos-methyl, and chlorpyrifos) in water samples followed by high-performance liquid chromatography diode array detection. The sorbent was prepared from a glycidyl methacrylate-based polymer, modified with a silanizing agent, followed by immobilization of MNPs on the surface of the material. The sorbent was characterized by scanning electron microscopy and Fourier transform infrared spectroscopy. Comparative studies of this support were done both in conventional SPE cartridge and MSPE approach. Several extraction parameters (loading pH, elution solvent, eluting volume, and loading flow rate) were investigated in detail. Under optimal conditions, the proposed sorbent gave an excellent enrichment efficiency of analytes and detection limits between 0.01 and 0.25 μg L−1. The recoveries of organophosphorus pesticides in spiked water samples were in the range of 71 98%, and the developed sorbent showed a high reusability (up to 50 uses without losses in recovery). The proposed method was satisfactorily applied to the analysis of these pesticides in water samples from different sources.This work was supported by projects CTQ2014-52765-R (MINECO of Spain and FEDER) and PROMETEO/2016/145 (Conselleria de Educacion, Investigacion, Cultura y Deporte of Generalitat Valenciana, Spain).Meseguer-Lloret, S.; Torres-Cartas, S.; Catalá-Icardo, M.; Simó-Alfonso, EF.; Herrero-Martínez, JM. (2017). Extraction and preconcentration of organophosphorus pesticides in water by using a polymethacrylate-based sorbent modified with magnetic nanoparticles. 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Determination of 3,5,6-trichloro-2-pyridinol, phoxim and chlorpyrifos-methyl in water samples using a new pretreatment method coupled with high-performance liquid chromatography. J Sep Sci. 2016;38:4204–10.Báez ME, Rodríguez M, Lastra O, Contreras P. Solid phase extraction of organophosphorus, triazine, and triazole-derived pesticides from water samples. A critical study. J High Resolut Chrom. 1997;20:591–6.Rocha AA, Monteiro SH, Andrade GCRM, Vilca FZ, Tornisielo CL. Monitoring of pesticides residues in surface and subsurface waters, sediments and fish in center-pivot irrigation areas. J Braz Chem Soc. 2015;25(11):2269–78.Hadjmohammadi MR, Peyrovi M, Biparva P. Comparison of C18 silica and multi-walled carbon nanotubes as the adsorbents for the solid-phase extraction of Chlorpyrifos and Phosalone in water samples using HPLC. J Sep Sci. 2010;33:1044–51.Pelit L, Dizdas TN. 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Multiresponse optimization of magnetic solid phase extraction based on carbon coated Fe3O4 nanoparticles using desirability function approach for the determination of the organophosphorus pesticides in aquatic samples by HPLC-UV. Talanta. 2012;99:13–21.Yan S, Qi TT, Chen DW, Li Z, Li XJ, Pan SY. Magnetic solid-phase extraction based on magnetite/reduced graphene oxide nanoparticles for determination of trace isocarbophos residues in different matrices. J Chromatogr A. 2014;1347:30–8.Tavakoli M, Hajimahmoodi M, Shemirani F. Trace level monitoring of pesticides in water samples using fatty acid coated magnetic nanoparticles prior to GC-MS. Anal Methods. 2014;6:2988–97.Tang Q, Wang X, Yu F, Qiao X, Xu Z. Simultaneous determination of ten organophosphorus pesticide residues in fruits by gas chromatography coupled with magnetic separation. J Sep Sci. 2014;27:820–7.Shen H, Zhu Y, Wen X, Zhuang Y. 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    Organic Anion Transporter 5 (Oat5) Urinary Excretion Is a Specific Biomarker of Kidney Injury: Evaluation of Urinary Excretion of Exosomal Oat5 after N-Acetylcysteine Prevention of Cisplatin Induced Nephrotoxicity

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    Cisplatin is a commonly used chemotherapeutic agent. Its main side-effect is nephrotoxicity. It was reported that the organic anion transporter 5 (Oat5) urinary excretion is elevated, implying renal perturbation, when no modifications of traditional markers of renal damage are still observed in cisplatin-induced acute kidney injury (AKI). It was also demonstrated that Oat5 is excreted in urine by the exosomal pathway. This study was designated to demonstrate the specific response of the urinary excretion of exosomal Oat5 to kidney injury independently of other cisplatin toxic effects, in order to strengthen Oat5 urinary levels as a specific biomarker of AKI. To accomplish that aim, we evaluated if urinary excretion of exosomal Oat5 returns to its basal levels when cisplatin renal damage is prevented by the coadministration of the renoprotective compound N-acetylcysteine. Four days after cisplatin administration, AKI was induced in cisplatin-treated male Wistar rats (Cis group), as it was corroborated by increased urea and creatinine plasma levels. Tubular damage was also observed. In cotreated animals (Cis + NAC group), plasma urea and creatinine concentrations tended to return to their basal values, and tubular damage was improved. Urinary excretion of exosomal Oat5 was notably increased in the Cis group, but when renal injury was ameliorated by N-acetylcysteine coadministration, that increase was undetected. So, in this work we observed that urinary excretion of exosomal Oat5 was only increased if renal insult is produced, demonstrating its specificity as a renal injury biomarker.Fil: Bulacio, Romina Paula. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Anzai, Naohiko. Dokkyo Medical University; JapónFil: Ouchi, Motoshi. Dokkyo Medical University; JapónFil: Torres, Adriana Monica. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    Maternal smoking in pregnancy and blood pressure during childhood and adolescence: a meta-analysis

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    rterial hypertension during childhood or adolescence is rising, and smoking during pregnancy may constitute a modifiable risk factor. This study aims to evaluate the effect of maternal smoking during pregnancy on diastolic (DBP) and systolic blood pressure (SBP) in childhood and adolescence. A bibliographic search was conducted in PubMed, Embase, and CENTRAL databases in March 2022. Meta-analysis was performed with the difference in mean-adjusted SBP/DBP of children and adolescents aged 3–17 years, according to maternal smoking/non-smoking in pregnancy. A random effects model was applied; a leave-one-out analysis and meta-analysis by subgroups were performed. A modified Newcastle–Ottawa scale was used to assess the quality of the studies. Evidence levels were rated using the GRADE system. Fifteen studies were included in the meta-analysis; all of them evaluated the mean-adjusted SBP difference in children or adolescents (N = 73,448), and 6 also that of DBP (N = 31,459). Results showed that maternal smoking during pregnancy significantly increased SBP (β = 0.31 mmHg 95% CI 0.14–0.49). A greater increase in mean-adjusted SBP was observed in those studies that completed the recruitment before 1990, were conducted in non-European countries, used standard mercury or manual sphygmomanometry, adjusted for birth weight, and were in the lowest quality subgroup. No significant association was found for DBP. The GRADE level of evidence was low for SBP and very low for DBP. Conclusion: Smoking in pregnancy might increase SBP in childhood and adolescence. Due to the low level of evidence, solid inferences cannot be drawn about the clinical relevance of these findings.S

    Preparation of organic monolithic columns in polytetrafluoroethylene tubes for reversed-phase liquid chromatography

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    [EN] In this work, a method for the preparation and anchoring of polymeric monoliths in a polytetrafluoroethylene (PTFE) tubing as a column housing for microbore HPLC is described. In order to assure a covalent attachment of the monolith to the inner wall of the PTFE tube, a two-step procedure was developed. Two surface etching reagents, a commercial sodium naphthalene solution (Fluoroetch®), or mixtures of H2O2 and H2SO4, were tried and compared. Then, the obtained hydroxyl groups on the PTFE surface were modified by methacryloylation. Attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy and scanning electron microscopy (SEM) confirmed the successful modification of the tubing wall and the stable anchorage of monolith to the wall, respectively. Special emphasis was also put on the reduction of the unwanted effects of shrinking of monolith during polymerization, by using an external proper mold and by selecting the adequate monomers in order to increase the flexibility of the polymer. Poly(glycidyl methacrylate-co-divinylbenzene) monoliths were in situ synthesized by thermal polymerization within the confines of surface-vinylized PTFE tubes. The modified PTFE tubing tightly held the monolith, and the monolithic column exhibited good pressure resistance up to 20 MPa. The column performance was also evaluated via the isocratic separation of a series of alkylbenzenes in the reversed-phase mode. The optimized monolithic columns gave plate heights ranged between 70 and 80 um. The resulting monoliths were also satisfactorily applied to the separation of proteins.This work was supported by projects CTQ2014-52765-R (MINECO of Spain and Fondo Europeo de Desarrollo Regional, FEDER) and PROMETEO/2016/145 (Conselleria d'Educacio, Investigacio, Cultura i Esport, Generalitat Valenciana, Spain). The authors also thank Dr. P. Amoros del Toro from Institute of Materials Science (University of Valencia) and Dr. S. Armenta from Department of Analytical Chemistry for their help in surface area and FT-IR measurements, respectively.Catalá-Icardo, M.; Torres-Cartas, S.; Meseguer-Lloret, S.; Gómez Benito, C.; Carrasco-Correa, E.; Simó-Alfonso, EF.; Ramis-Ramos, G.... (2017). Preparation of organic monolithic columns in polytetrafluoroethylene tubes for reversed-phase liquid chromatography. Analytica Chimica Acta. 960:160-167. https://doi.org/10.1016/j.aca.2017.01.01216016796
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