1
|
Nishimura T. [Steps to Regulatory Science]. YAKUGAKU ZASSHI 2023; 143:565-580. [PMID: 37394453 DOI: 10.1248/yakushi.22-00221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
The research achievements in the field of regulatory science from the beginning of my research are described in an overview. First, I was interested in the complexity of development and pursued my studies on the mechanisms of DNA replication and repair, the mutagenicity of air pollutants, and the oncogene. After researching new phenomena based on the discovery of basic research in molecular/biochemistry, my research interests turned to the field of regulatory science which applies scientific evidence to social systems. I was able to successfully contribute to the field of drinking water quality in Japan through the establishment of drinking water quality standards and standard values, primarily for organic and agricultural chemicals, the development of analysis techniques, and the creation of an organization for ensuring safety. Research on the water quality in public water areas, which are also the sources of drinking water, was another subject in which I was involved. I took part in developing the concept and evaluation methodology for the environmental impact assessment of active pharmaceutical ingredients as well as conducting environmental monitoring on urban rivers in Japan. I have also been engaged in studies on the security and safety of human health with an ecosystem conservation background. It has been a great pleasure to collaborate on research projects with so many people toward a common aim.
Collapse
Affiliation(s)
- Tetsuji Nishimura
- Graduate School of Environmental Informations, Teikyo Heisei University
| |
Collapse
|
2
|
Wicht K, Baert M, Muller M, Bandini E, Schipperges S, von Doehren N, Desmet G, de Villiers A, Lynen F. Comprehensive two-dimensional temperature-responsive × reversed phase liquid chromatography for the analysis of wine phenolics. Talanta 2022; 236:122889. [PMID: 34635268 DOI: 10.1016/j.talanta.2021.122889] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 09/13/2021] [Accepted: 09/14/2021] [Indexed: 11/18/2022]
Abstract
Phenolic compounds are an interesting class of natural products because of their proposed contribution to health benefits of foods and beverages and as a bio-source of organic (aromatic) building blocks. Phenolic extracts from natural products are often highly complex and contain compounds covering a broad range in molecular properties. While many 1D-LC and mass spectrometric approaches have been proposed for the analysis of phenolics, this complexity inevitably leads to challenging identification and purification. New insights into the composition of phenolic extracts can be obtained through online comprehensive two-dimensional liquid chromatography (LC × LC) coupled to photodiode array and mass spectrometric detection. However, several practical hurdles must be overcome to achieve high peak capacities and to obtain robust methods with this technique. In many LC × LC configurations, refocusing of analytes at the head of the 2D column is hindered by the high eluotropic strength of the solvent transferred from the 1D to the 2D, leading to peak breakthrough or broadening. LC × LC combinations whereby a purely aqueous mobile phase is used in the 1D and RPLC is used in the 2D are unaffected by these phenomena, leading to more robust methods. In this contribution, the combination of temperature-responsive liquid chromatography (TRLC) with RPLC is used for the first time for the analysis of phenolic extracts of natural origin to illustrate the potential of this alternative combination for natural product analyses. The possibilities of the combination are investigated through analysis of wine extracts by TRLC × RPLC-DAD and TRLC × RPLC-ESI-MS.
Collapse
Affiliation(s)
- Kristina Wicht
- Separation Science Group, Department of Organic and Macromolecular Chemistry, Ghent University, Krijgslaan 281-S4, B-9000, Ghent, Belgium
| | - Mathijs Baert
- Separation Science Group, Department of Organic and Macromolecular Chemistry, Ghent University, Krijgslaan 281-S4, B-9000, Ghent, Belgium
| | - Magriet Muller
- Department of Chemistry and Polymer Science, University of Stellenbosch, Private Bag X1, ZA-7602, Matieland, South Africa
| | - Elena Bandini
- Separation Science Group, Department of Organic and Macromolecular Chemistry, Ghent University, Krijgslaan 281-S4, B-9000, Ghent, Belgium
| | - Sonja Schipperges
- Agilent Technologies, Hewlett Packard St 8, D-76337, Waldbronn, Germany
| | - Norwin von Doehren
- Agilent Technologies, Netherlands BV, NL-4330, EA, Middelburg, Netherlands
| | - Gert Desmet
- Department of Chemical Engineering, Vrije Universiteit Brussel, Pleinlaan 2, B-1050, Brussel, Belgium
| | - André de Villiers
- Department of Chemistry and Polymer Science, University of Stellenbosch, Private Bag X1, ZA-7602, Matieland, South Africa
| | - Frederic Lynen
- Separation Science Group, Department of Organic and Macromolecular Chemistry, Ghent University, Krijgslaan 281-S4, B-9000, Ghent, Belgium.
| |
Collapse
|
3
|
Matsuura M, Ohshima M, Hiruta Y, Nishimura T, Nagase K, Kanazawa H. LAT1-Targeting Thermoresponsive Fluorescent Polymer Probes for Cancer Cell Imaging. Int J Mol Sci 2018; 19:E1646. [PMID: 29865203 PMCID: PMC6032285 DOI: 10.3390/ijms19061646] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 05/24/2018] [Accepted: 05/25/2018] [Indexed: 01/31/2023] Open
Abstract
L-type amino acid transporter 1 (LAT1) is more highly expressed in cancer cells compared with normal cells. LAT1 targeting probes would therefore be a promising tool for cancer cell imaging. In this study, LAT1-targeting thermoresponsive fluorescent polymer probes based on poly(N-isopropylacrylamide-co-N,N-dimethylacrylamide) (P(NIPAAm-co-DMAAm)) were synthesized and their affinity for LAT1 was evaluated. The synthesized polymer probes interacted with LAT1 on HeLa cells, and inhibition of l-[³H]-leucine, one of the substrates for LAT1 uptake, was investigated. l-Tyrosine-conjugated P(NIPAAm-co-DMAAm) inhibited the uptake of l-[³H]-leucine, while P(NIPAAm-co-DMAAm) and l-phenylalanine-conjugated P(NIPAAm-co-DMAAm) did not. This result indicated that l-tyrosine-conjugated polymer has a high affinity for LAT1. The fluorescent polymer probes were prepared by modification of a terminal polymer group with fluorescein-5-maleimide (FL). Above the polymer transition temperature, cellular uptake of the polymer probes was observed because the polymers became hydrophobic, which enhanced the interaction with the cell membrane. Furthermore, quantitative analysis of the fluorescent probe using flow cytometry indicated that l-tyrosine-conjugated P(NIPAAm-co-DMAAm)-FL shows higher fluorescence intensity earlier than P(NIPAAm-co-DMAAm)-FL. The result suggested that cellular uptake was promoted by the LAT1 affinity site. The developed LAT1-targeting thermoresponsive fluorescent polymer probes are expected to be useful for cancer cell imaging.
Collapse
Affiliation(s)
- Minami Matsuura
- Faculty of Pharmacy, Keio University, 1-5-30, Shibakoen, Minato-ku, Tokyo 105-8012, Japan.
| | - Mariko Ohshima
- Faculty of Pharmacy, Keio University, 1-5-30, Shibakoen, Minato-ku, Tokyo 105-8012, Japan.
| | - Yuki Hiruta
- Department of Applied Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan.
| | - Tomohiro Nishimura
- Faculty of Pharmacy, Keio University, 1-5-30, Shibakoen, Minato-ku, Tokyo 105-8012, Japan.
| | - Kenichi Nagase
- Faculty of Pharmacy, Keio University, 1-5-30, Shibakoen, Minato-ku, Tokyo 105-8012, Japan.
| | - Hideko Kanazawa
- Faculty of Pharmacy, Keio University, 1-5-30, Shibakoen, Minato-ku, Tokyo 105-8012, Japan.
| |
Collapse
|
4
|
Determination of halosulfuron-methyl herbicide in sugarcane juice and tomato by capillary electrophoresis–tandem mass spectrometry. Food Chem 2015; 175:82-4. [DOI: 10.1016/j.foodchem.2014.11.137] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 11/14/2014] [Accepted: 11/22/2014] [Indexed: 11/21/2022]
|
5
|
Lorenzo RA, Carro AM, Concheiro A, Alvarez-Lorenzo C. Stimuli-responsive materials in analytical separation. Anal Bioanal Chem 2015; 407:4927-48. [DOI: 10.1007/s00216-015-8679-1] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Revised: 03/30/2015] [Accepted: 04/07/2015] [Indexed: 02/07/2023]
|
6
|
Feng M, Li W, Hao X, Han L. Determination of halosulfuron-methyl residues and dissipation in wheat by QuEChERS and LC-MS/MS. Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2014; 31:1879-85. [DOI: 10.1080/19440049.2014.961176] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
7
|
He Z, Liu D, Li R, Zhou Z, Wang P. Magnetic solid-phase extraction of sulfonylurea herbicides in environmental water samples by Fe3O4@dioctadecyl dimethyl ammonium chloride@silica magnetic particles. Anal Chim Acta 2012; 747:29-35. [DOI: 10.1016/j.aca.2012.08.015] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Revised: 07/15/2012] [Accepted: 08/09/2012] [Indexed: 12/01/2022]
|
8
|
Preparation of dual temperature/pH-sensitive polyampholyte gels and investigation of their protein adsorption behaviors. Sep Purif Technol 2012. [DOI: 10.1016/j.seppur.2012.05.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
9
|
Feng Z, Zhu Y, Ni C. Preparation of Composites of Silica/PNIPAm by Coupling Reaction and Their Application in HPLC. INTERNATIONAL JOURNAL OF POLYMER ANALYSIS AND CHARACTERIZATION 2012. [DOI: 10.1080/1023666x.2012.638745] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
|
10
|
Catalá-Icardo M, López-Paz JL, Peña-Bádena A. FI-photoinduced chemiluminescence method for diuron determination in water samples. ANAL SCI 2011; 27:291-6. [PMID: 21415512 DOI: 10.2116/analsci.27.291] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A new method for the determination of the herbicide diuron, using a flow injection manifold and photoinduced chemiluminescence detection, is presented. The pesticide, in basic medium, was irradiated on-line with UV light (254 nm) for 53 s. A short discussion about the possible irradiation products is included. The chemiluminescent response of the photoproducts was induced by oxidation with potassium ferricyanide in phosphate buffer at pH 11.5. The method permitted the quantification of diuron over the 0.1-4.0 mg L(-1) range, with a detection limit (S/N = 3) of 20 µg L(-1) when the method was applied directly. However, the use of solid phase extraction (SPE) performed with C(18) cartridges allowed us to achieve a limit of detection of 0.4 µg L(-1) and a 1.5-30 µg L(-1) dynamic range. The method was successfully applied to the diuron determination in samples of water from different sources (spring, ground, mineral, irrigation, sea and tap waters) with a low consumption of reagents.
Collapse
Affiliation(s)
- Mónica Catalá-Icardo
- Instituto de Investigación para la Gestión Integrada de Zonas Costeras, Escuela Politécnica Superior de Gandía, Universidad Politécnica de Valencia, Grao de Gandía, Valencia, Spain.
| | | | | |
Collapse
|
11
|
Trace determination of sulfonylurea herbicides in water and grape samples by capillary zone electrophoresis using large volume sample stacking. Anal Bioanal Chem 2010; 397:2593-601. [DOI: 10.1007/s00216-010-3812-7] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2010] [Revised: 04/26/2010] [Accepted: 04/30/2010] [Indexed: 10/19/2022]
|
12
|
Ouyang X, Zhang W, Xu J, Chang N, Pan C, Zhang J, Niu W. Determination of sulfonylurea herbicides in water using solid-phase extraction followed by liquid chromatography with electrospray ion trap mass spectrometry. JOURNAL OF ANALYTICAL CHEMISTRY 2009. [DOI: 10.1134/s1061934809090111] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
13
|
Chen H, Zhang J, Qian Z, Liu F, Chen X, Hu Y, Gu Y. In vivo non-invasive optical imaging of temperature-sensitive co-polymeric nanohydrogel. NANOTECHNOLOGY 2008; 19:185707. [PMID: 21825703 DOI: 10.1088/0957-4484/19/18/185707] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Assessment of hyperthermia in pathological tissue is a promising strategy for earlier diagnosis of malignant tumors. In this study, temperature-sensitive co-polymeric nanohydrogel poly(N-isopropylacrylamide-co-acrylic acid) (PNIPA-co-AA) was successfully synthesized by the precipitation polymerization method. The diameters of nanohydrogels were controlled to be less than 100 nm. Also the lower critical solution temperature (LCST, 40 °C) was manipulated above physiological temperature after integration of near-infrared (NIR) organic dye (heptamethine cyanine dye, HMCD) within its interior cores. NIR laser light (765 nm), together with sensitive charge coupled device (CCD) cameras, were designed to construct an NIR imaging system. The dynamic behaviors of PNIPA-co-AA-HMCD composites in denuded mice with or without local hyperthermia treatment were real-time monitored by an NIR imager. The results showed that the PNIPA-co-AA-HMCD composites accumulated in the leg treated with local heating and diffused much slower than that in the other leg without heating. The results demonstrated that the temperature-responsive PNIPA-co-AA-HMCD composites combining with an NIR imaging system could be an effective temperature mapping technique, which provides a promising prospect for earlier tumor diagnosis and thermally related therapeutic assessment.
Collapse
Affiliation(s)
- Haiyan Chen
- Department of Analytical Chemistry, School of Basic Science, 24 Shennong Road, China Pharmaceutical University, Nanjing 210009, People's Republic of China. Department of Biomedical Engineering, School of Life Science and Technology, 24 Shennong Road, China Pharmaceutical University, Nanjing 210009, People's Republic of China
| | | | | | | | | | | | | |
Collapse
|
14
|
Zarzycki PK. Simple horizontal chamber for thermostated micro-thin-layer chromatography. J Chromatogr A 2008; 1187:250-9. [PMID: 18299134 DOI: 10.1016/j.chroma.2008.02.013] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2008] [Revised: 02/04/2008] [Accepted: 02/06/2008] [Indexed: 10/22/2022]
|
15
|
Maharjan P, Woonton BW, Bennett LE, Smithers GW, DeSilva K, Hearn MT. Novel chromatographic separation — The potential of smart polymers. INNOV FOOD SCI EMERG 2008. [DOI: 10.1016/j.ifset.2007.03.028] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
16
|
Tokuyama H, Iwama T. Temperature-swing solid-phase extraction of heavy metals on a poly(N-isopropylacrylamide) hydrogel. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2007; 23:13104-13108. [PMID: 17999542 DOI: 10.1021/la701728n] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The feasibility of temperature-swing adsorption of heavy metals on a thermosensitive N-isopropylacrylamide (NIPA) hydrogel was examined. We have proposed a novel temperature-swing solid-phase extraction (TS-SPE) technique. First, a metal ion in an aqueous solution is complexed with an extractant. Subsequently, the metal-extractant complexes (or micelles) are adsorbed onto the NIPA hydrogel through a hydrophobic interaction above the lower critical solution temperature (LCST). Finally, the metal-extractant complexes are desorbed from the NIPA hydrogel after it is cooled below the LCST. In a model system consisting of Cu(II) ions, sodium n-dodecylbenzenesulfonate (SDBS), and NIPA hydrogel, the proposed TS-SPE technique has been successfully conducted. The following observations can be made: the amount of adsorbed Cu(II) ions increases with the increase in temperature, the maximum adsorption is attained at a temperature above the LCST, and the hydrogel adsorbs and desorbs Cu(II) ions reversibly due to the temperature-swing between 10 and 40 degrees C. The LCSTs of poly(NIPA) in aqueous SDBS solutions with/without CuCl2 and the surface tensions of their solutions suggest that the hydrophobicity of the complex Cu(DBS)2 is greater than the hydrophobicities of SDBS and DBS. In addition to the separation of heavy metals, TS-SPE is potentially applicable to cases such as the separation of biological molecules by means of metal-ion affinity.
Collapse
Affiliation(s)
- Hideaki Tokuyama
- Department of Chemical Engineering, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8603, Japan.
| | | |
Collapse
|
17
|
Ayano E, Suzuki Y, Kanezawa M, Sakamoto C, Morita-Murase Y, Nagata Y, Kanazawa H, Kikuchi A, Okano T. Analysis of melatonin using a pH- and temperature-responsive aqueous chromatography system. J Chromatogr A 2007; 1156:213-9. [PMID: 17292374 DOI: 10.1016/j.chroma.2007.01.063] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2006] [Revised: 01/18/2007] [Accepted: 01/19/2007] [Indexed: 11/22/2022]
Abstract
A new method for the qualitative and quantitative analysis of an intracerebral hormone, such as melatonin, has been proposed, utilizing newly designed copolymers that include ion-exchange groups. These copolymers responded to both the temperature and the pH, and the copolymers were modified with cross-linked hydrogel applied onto aminopropyl silica beads. The products were evaluated as HPLC packing materials for a pH- and temperature-responsive chromatography. The property of the surface of the stationary phase was altered from hydrophilic to hydrophobic, and from charged to non-charged by changes in both the temperature and the pH. In the chromatographic system, we investigated how to change the retention of melatonin by varying the temperature. A pH- and temperature-responsive chromatography is expected to be useful for the separation of pharmaceuticals and biomolecules.
Collapse
Affiliation(s)
- Eri Ayano
- Department of Physical Pharmaceutical Chemistry, Kyoritsu University of Pharmacy, Tokyo, Japan
| | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Lynen F, Heijl JMD, Prez FED, Brown R, Szucs R, Sandra P. Evaluation of the Temperature Responsive Stationary Phase Poly(N-isopropylacrylamide) in Aqueous LC for the Analysis of Small Molecules. Chromatographia 2007. [DOI: 10.1365/s10337-007-0301-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
19
|
Zhou Q, Xiao J, Wang W. Comparison of Multiwalled Carbon Nanotubes and a Conventional Absorbent on the Enrichment of Sulfonylurea Herbicides in Water Samples. ANAL SCI 2007; 23:189-92. [PMID: 17297231 DOI: 10.2116/analsci.23.189] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Recently, multiwalled carbon nanotubes (MWCNTs) have been at the center of attention because of their applications in many fields. Efforts to investigate the possibility of MWCNTs as SPE absorbents for the enrichment of environmental pollutants yielded positive results. The goal of the present work was to compare the enrichment power of MWCNTs with that of regular adsorbents, such as C18 silica for SPE of five sulfonylurea herbicides. The results indicated that multiwalled carbon nanotubes were very suitable for the preconcentration of sulfonylurea herbicides in complex water samples, yielding better recoveries. C18 gave a lightly lower enrichment performance, and could not enrich nicosulfuron in complex samples. All of these experimental results indicated that multiwalled carbon nanotubes could be used as a valuable alternative adsorbent for the SPE of sulfonylurea herbicides in many real water samples.
Collapse
Affiliation(s)
- Qingxiang Zhou
- School of Chemistry and Environmental Sciences, Henan Normal University, Henan Key Laboratory for Environmental Pollution Control, Zinziang, PR China.
| | | | | |
Collapse
|
20
|
KANEZAWA M, NAMBU K, SUZUKI Y, NISHIKAWA M, KANAZAWA H. Novel Analytical System Using Environment-Responsive Polymer. BUNSEKI KAGAKU 2007. [DOI: 10.2116/bunsekikagaku.56.397] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Masahito KANEZAWA
- Department of Physical Pharmaceutical Chemistry, Kyoritsu University of Pharmacy
| | - Kyoko NAMBU
- Department of Physical Pharmaceutical Chemistry, Kyoritsu University of Pharmacy
| | - Yusuke SUZUKI
- Department of Physical Pharmaceutical Chemistry, Kyoritsu University of Pharmacy
| | - Mayumi NISHIKAWA
- Department of Physical Pharmaceutical Chemistry, Kyoritsu University of Pharmacy
| | - Hideko KANAZAWA
- Department of Physical Pharmaceutical Chemistry, Kyoritsu University of Pharmacy
| |
Collapse
|
21
|
Yoshida M, Langer R, Lendlein A, Lahann J. From Advanced Biomedical Coatings to Multi‐Functionalized Biomaterials. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/15583720600945394] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
22
|
Ye G, Zhang W, Cui X, Pan C, Jiang S. Determination and Quantitation of Ten Sulfonylurea Herbicides in Soil Samples Using Liquid Chromatography with Electrospray Ionization Mass Spectrometric Detection. CHINESE JOURNAL OF ANALYTICAL CHEMISTRY 2006. [DOI: 10.1016/s1872-2040(07)60001-2] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
23
|
Vanhoenacker G, Sandra P. Elevated temperature and temperature programming in conventional liquid chromatography – fundamentals and applications. J Sep Sci 2006; 29:1822-35. [PMID: 16970186 DOI: 10.1002/jssc.200600160] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Temperature, as a powerful variable in conventional LC is discussed from a fundamental point of view and illustrated with applications from the author's laboratory. Emphasis is given to the influence of temperature on speed, selectivity, efficiency, detectability, and mobile phase composition (green chromatography). The problems accompanying the use of elevated temperature and temperature programming in LC are reviewed and solutions are described. The available stationary phases for high temperature operation are summarized and a brief overview of recent applications reported in the literature is given.
Collapse
|
24
|
Ayano E, Kanazawa H. Aqueous chromatography system using temperature-responsive polymer-modified stationary phases. J Sep Sci 2006; 29:738-49. [PMID: 16830486 DOI: 10.1002/jssc.200500485] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Extensive research has been carried out on functional polymers which are currently playing important roles in various fields such as medicine and engineering. Such functional polymers which respond to various kinds of stimuli are termed 'intelligent materials'. Poly(N-isopropylacrylamide) (PNIPAAm), a temperature-responsive polymer, was utilized as a chromatography column matrix modifier for a novel chromatographic approach in which only aqueous media are used as a mobile phase. The ability of the developed temperature-responsive chromatography system to separate solutes without using an organic solvent is advantageous from the point of view of maintaining the structure and activity of bioactive compounds. Recently, we designed and synthesized a new pH- and temperature-responsive copolymer as a representative of such environment-responsive polymers and grafted it onto aminopropyl silica beads. The products were evaluated as HPLC packing materials for separation systems based on a new concept, according to which the properties of the stationary phase surface are altered by external stimuli such as pH and temperature. This chromatography system utilizing the PNIPAAm copolymer is very useful for the separation of bioactive substances, such as proteins and peptides, because separation in the aqueous mobile phase is controlled solely by changing the temperature. This analytical system reduces organic waste because no organic solvent is used to separate the solutes and can therefore be classified as environmentally friendly. Future medical and pharmaceutical applications are expected.
Collapse
Affiliation(s)
- Eri Ayano
- Department of Physical Pharmaceutical Chemistry, Kyoritsu University of Pharmacy, Tokyo, Japan
| | | |
Collapse
|
25
|
Ayano E, Okada Y, Sakamoto C, Kanazawa H, Kikuchi A, Okano T. Study of temperature-responsibility on the surfaces of a thermo-responsive polymer modified stationary phase. J Chromatogr A 2006; 1119:51-7. [PMID: 16487534 DOI: 10.1016/j.chroma.2006.01.126] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2005] [Revised: 01/25/2006] [Accepted: 01/30/2006] [Indexed: 10/25/2022]
Abstract
We investigated a thermo-sensitive polymer, poly(N-isopropylacrylamide) (PNIPAAm), which is the basis of an HPLC stationary phase. We prepared a PNIPAAm terminally-modified surface. In this study, we investigated the effect of PNIPAAm on the surface of a stationary phase on separation based on changes of the retention time with the temperature step gradient. As the temperature changed the surface property of the stationary phase switched from hydrophilic to hydrophobic. The retention on the polymer-modified stationary phase remarkably changed upon changing the temperature. Using a column packed with PNIPAAm-modified silica, the separation of steroids was carried out by changing the temperature. With increasing temperature, an increased interaction between solutes and PNIPAAm-grafted surfaces of the stationary phases was observed. A temperature-dependent resolution of steroids was achieved using only water as a mobile phase. The PNIPAAm-modified surface of the stationary phase exhibited temperature-controlled hydrophilic-hydrophobic changes. The drastic and reversible surface hydrophilic-hydrophobic property alteration for PNIPAAm terminally-grafted surfaces should be due to rapid changes in the polymer hydration state around the polymer's transition temperature. A solvent gradient elution-like effect could be achieved with a single mobile phase by programmed temperature changes during chromatographic runs. This system should be highly useful to control the function and property of the stationary phase for HPLC only by changing the temperature with an aqueous solvent.
Collapse
Affiliation(s)
- Eri Ayano
- Department of Physical Pharmaceutical Chemistry, Kyoritsu University of Pharmacy, Minato-ku, Tokyo, Japan
| | | | | | | | | | | |
Collapse
|
26
|
Zarzycki PK, Kulhanek KM, Smith R, Clifton VL. Determination of steroids in human plasma using temperature-dependent inclusion chromatography for metabolomic investigations. J Chromatogr A 2005; 1104:203-8. [PMID: 16364333 DOI: 10.1016/j.chroma.2005.11.119] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2005] [Revised: 11/29/2005] [Accepted: 11/30/2005] [Indexed: 10/25/2022]
Abstract
Clinical and metabolomic investigations of complex human fluids require cost-effective methodologies that can rapidly assess the steroid hormone milieu of individual samples. The efficiency of quantification of many steroids is limited using immunoassays as these methods can only measure a single component of biological samples and are dependent upon the specificity of the antiserum used in the protocol. In this study, we optimised the solid-phase extraction protocol for the extraction of a range of steroids of varied polarity from estetrol to progesterone from human plasma. The final SPE procedure for efficient extraction of steroids was a washing mixture of 5 ml of 30% methanol and an elution solvent of 2 ml of 100% methanol using 0.5 g C-18 cartridges. This protocol resulted in a high recovery rate, ranging from 85.2 to 99.9% for both the internal standard (7,8-dimethoxyflavone) and steroids of interest. We also improved the separation methodology of our previous work using temperature dependent inclusion chromatography with a mobile phase composition of 35% acetonitrile and 12 mM of beta-cyclodextrin at 29 degrees C. Under these conditions most of the fluid components including estetrol were detected in the first 10 min with progesterone appearing at 43 min. This method is simplistic, inexpensive and reproducible with the capabilities of accurate quantification of steroids. Therefore it could have numerous clinical and metabolomic applications.
Collapse
Affiliation(s)
- Paweł K Zarzycki
- Laboratory of Toxicology, Department of Environmental Biology, Technical University of Koszalin, Sniadeckich 2, 75-453 Koszalin, Poland.
| | | | | | | |
Collapse
|
27
|
AYANO E, KANAZAWA H. Development of Temperature-Responsive Chromatography Using Functional Polymers. BUNSEKI KAGAKU 2005. [DOI: 10.2116/bunsekikagaku.54.593] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Eri AYANO
- Physical Pharmaceutical Chemistry, Kyoritsu University of Pharmacy
| | - Hideko KANAZAWA
- Physical Pharmaceutical Chemistry, Kyoritsu University of Pharmacy
| |
Collapse
|