Determination of formation constants for .beta.-cyclodextrin complexes of anthracene and pyrene using reversed-phase liquid chromatography

Anigbogu, Vincent C.; Peña, Arsenio Muñoz de la; Ndou, Thilivhali T.; Warner, Isiah M.

doi:10.1021/ac00029a007

Cited by 45 publications

(20 citation statements)

References 39 publications

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“…If this procedure has often been used as described in the original publication [59,[65][66][67], better results are obtained with variants of this method [68,69]. HPLC provides another way for obtaining the complexation constants of analytes with CDs [70,71]. With such chromatographic methods, the association constants of the guest: CD complexes may be obtained even if the spectroscopic changes resulting from the inclusion are absent or not significative.…”

Section: What It Takes To Fully Characterize One Inclusion Complexmentioning

confidence: 99%

“…HPLC with fluorescence detection is used also to obtain the formation constants of analytes with the cyclodextrins added to the mobile phase. Two recent studies use the technique, one on pyrene and anthracene [71] and one on a set of new derivatization agents mostly derived from carbazole [179].…”

Section: Micelles and Cyclodextrins In Separation Science Using Fluormentioning

confidence: 99%

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Luminescence in organized media and supramolecular interactions:physicochemical aspects and applications

Lerner¹,

Martín²

2000

Analusis

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Introduction Molecular luminescence of analytes in organized media or in supramolecular complexes of cyclodextrinsThe photophysical and photochemical behaviour of molecules complexed to cyclodextrins (CD) is generally different from their behaviour in solution. The first observations in the field were qualitative and were related to the increased stabilisation of labile molecules, mostly drugs, against photodegradation when complexed to natural cyclodextrins [1]. Complexation by CD's was then the preferred subject for those involved in supramolecular chemistry and drug vectorisation techniques [2] as well as in separation techniques [3][4][5]. Stabilization of a molecule against photochemical degradation is still very important in the field of pharmaceutical sciences. A recent example is the stabilisation of promazine as an inclusion complex with β-cyclodextrin [6]. Other photochemists were attracted quite early to this field of research and initiated studies, which were mostly photophysical in nature [7,8]. The key observation was that the formation of supramolecular complexes of analytes with cyclodextrins (CDs) resulted in an increase of their fluorescence quantum yield or even in the appearance of room temperature phosphorescence (RTP) [9][10][11][12]. This enhancement has been used to increase the sensitivity and the selectivity in both luminescence and chromatographic techniques [13-15].We will not say more about RTP with CDs as the subject will be developed in another contribution in the same issue of this Journal. However RTP is also observed in the solubilization of analytes in micellar colloïdal solutions and this field will be reviewed hereunder.These properties have been used to develop analytical techniques, which combine the selectivity of complexation with an enhanced emission [16][17][18][19]. In this way an improvement in the detection limits is obtained in many separation techniques such as HPLC, capillary electrophoresis (CE) or planar chromatography. Furthermore these molecular interactions allow to reveal or to stabilize new molecular forms or to turn species which are normally non-emitting into luminescent ones. All these aspects are reviewed hereunder after a short summary on the nature of the intermolecular interactions, which lie at the heart of these effects. Nature of the interactions between an analyte and a CD or a micelleWithout going into a thorough analysis of the origin of the interactions which exist between molecules in dense media which concern us here, it seems useful to recall the most important factors which should be taken into account when any type of luminescence, fluorescence or phosphorescence is involved.

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Section: What It Takes To Fully Characterize One Inclusion Complexmentioning

confidence: 99%

Section: Micelles and Cyclodextrins In Separation Science Using Fluormentioning

confidence: 99%

Luminescence in organized media and supramolecular interactions:physicochemical aspects and applications

Lerner¹,

Martín²

2000

Analusis

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“…Cyclodextrins, cyclic non-reducing oligosaccharides, have been extensively used to obtain these inclusion complexes. In particular, many studies have focused on the ability of CDs to include guests of varying sizes in different stoichiometric ratios and several analytical applications of these complexes have been reported [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30].…”

mentioning

confidence: 99%

Room temperature phosphorescence in cyclodextrins. Analytical applications

Peña¹,

Mahedero²,

Sánchez³

2000

Analusis

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Surfactants which form micelles and cyclodextrins are two of the most common forms of organized media. Surfactants are known for their ability to self-assemble in water and/or organic solvents and form normal/reverse micelles above the critical micelle concentration (CMC). Micellar solubilization in surfactant solutions has been widely exploited in analytical chemistry. The formation of inclusion compounds, by using cyclodextrins as hosts, has been also frequently used to enhance the analytical responses of analytes by incorporation of guest molecules into the cyclodextrins hydrophobic cavity [1].The first observation of room temperature phosphorescence (RTP), using a microscopically organized media, used sodium dodecylsulfate (SDS) micelles in the presence of tallium [2]. Since then, several media have been investigated to stabilize the triplet-state in fluid solution at room temperature. Normal micelles, mainly sodium dodecylsulfate [3][4][5][6], cetyltrimethylammonium bromide (CTB) [7][8][9] and Triton X-100 [10] micelles, have been used in RTP analytical applications. As an alternative to the use of normal micelles, microemulsions, formed in heptane-SDS-1-pentanol, have been also reported for RTP obtention [11][12][13][14].Cyclodextrins (CDs) can form complexes with phosphors and heavy atom containing additives and these host-guest aggregates serve to populate and stabilize the fragile tripletstate, producing characteristic room temperature phosphorescence. These inclusion complexes induce an intense phosphorescence emission which is partially insensitive to Cyclodextrins are composed of D-glucose residues joined by α(1→4) linkages. α-, β-and γ-CDs, which are made up of six, seven and eight D-glucose residues, are the most common members of a CD family. These CDs are shaped like a truncated cone with a hollow, hydrophobic cavity in which a hydrophobic guest can be incorporated.Molecular encapsulation by means of molecular inclusion complex formation offers a new approach in analytical chemistry. Generally, the inclusion complex involves the spatial entrapment of a single guest molecule in the cavity of the host molecule, without the formation of any covalent bonds. Cyclodextrins, cyclic non-reducing oligosaccharides, have been extensively used to obtain these inclusion complexes. In particular, many studies have focused on the ability of CDs to include guests of varying sizes in different stoichiometric ratios and several analytical applications of these complexes have been reported [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30].It is well documented that, depending upon the host CD (i.e. α-, β-or γ-CD) and the size of the guest, different

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“…104 middle peaks. However, it took more than two hours to elute all eighteen compounds while peaks 2 and 3,4 and 5 were still not baseline resolved.…”

Section: Determination Of Solute-surfactant Binding Constantmentioning

confidence: 99%

“…Alcohols added to the mobile phase promoted the formation of cyclodextrin inclusion complexes with the polynuclear species by forming ternary complexes. The same authors also measured the formation constants for B-CD complexes of anthracene and pyrene using RPLC [104]. They found that pyrene complexation was not observed until tertyl-butyl alcohol or cyclopentanol was added to the mobile phase, and that the analyte:CD stoichiometry was 1:1 and 1:2 for anthracene and pyrene, respectively.…”

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Method development for high performance liquid chromatography: novel organic modifiers and column packing conditions

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This manuscript has been reproduced from the microfilm master. UMl films the text directly from the original or copy submitted. Thus, some thesis and dissertation copies are in typewriter face, while others may be from any type of computer printer.The quality of this reproduction is dependent upon the quality of the copy submitted. Broken or indistinct print, colored or poor quality illustrations and photographs, print bleedthrough, substandard margins, and improper alignment can adversely affect reproduction.In the unlikely event that the author did not send UMI a complete manuscript and there are missing pages, these will be noted. Also, if unauthorized copyright material had to be removed, a note will indicate the deletion.Oversize materials (e.g., maps, drawings, charts) are reproduced by sectioning the original, beguming at the upper left-hand comer and continuing from left to right in equal sections with small overlaps. Each original is also photographed in one exposure and is included in reduced form at the back of the book.Photographs included in the original manuscript have been reproduced xerographically in this copy. Higher quality 6" x 9" black and white photographic prints are available for any photographs or illustrations appearing in this copy for an additional charge. Contact UMI directly to order. 1996Signature was redacted for privacy.Signature was redacted for privacy.Signature was redacted for privacy. Dissertation OrganizationThis dissertation begins with a general introduction containing a literature review.References cited in the literature review are compiled in the reference section within the general introduction. This is then followed by four chapters all of which are in the format of research papers. They have been accepted, have been submitted or will soon be submitted for publication. A general conclusion section follows the four chapters. The second paper is similar to the publication version, although additional figures and tables have been added.Figures and tables are contained in the text of the paper at the appropriate location.References cited within each paper are listed after the conclusions of each paper. [70]. Indeed, it is amazing just to think about the popularity of HPLC from major components to trace analysis, from food, soil and water to poison, drug and trace evidence, from organic to inorganic analysis, firom natural to synthetic products, from peptides and proteins to RNA and DNA, from industry to clinics, from separation and pxirification to structure elucidation. The future of HPLC seems to be even brighter with gas chromatography, supercritical fluid chromatography, field flow fractionation and capillary electrophoresis to complement it. Higfai Performance Liquid Chromatography 4Although HPLC has become a well established technique, advances are still being made in the fundamental understanding of various separation mechanisms as well as improvements in equipment capabilities.In this dissertation, HPLC methods were developed for the separations of various org...

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Determination of formation constants for .beta.-cyclodextrin complexes of anthracene and pyrene using reversed-phase liquid chromatography

Cited by 45 publications

References 39 publications

Luminescence in organized media and supramolecular interactions:physicochemical aspects and applications

Luminescence in organized media and supramolecular interactions:physicochemical aspects and applications

Room temperature phosphorescence in cyclodextrins. Analytical applications

Method development for high performance liquid chromatography: novel organic modifiers and column packing conditions

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