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  • 1.
    Alexander, JN
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Poli, JB
    Markides, KE
    Evaluation of automated isocratic and gradient nano-liquid chromatography and capillary electrochromatography1999In: ANALYTICAL CHEMISTRY, ISSN 0003-2700, Vol. 71, no 13, p. 2398-2409Article in journal (Refereed)
    Abstract [en]

    An automated liquid nano-separation system has been developed for nano-liquid chromatography (nano-LC) and capillary electrochromatography (CEC) using both isocratic and gradient elution, One fused-silica nanocolumn, typically 75 mu m i x 39 cm (25 cm ef

  • 2.
    Barnidge, DR
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Nilsson, S
    Markides, KE
    A design for low-flow sheathless electrospray emitters1999In: ANALYTICAL CHEMISTRY, ISSN 0003-2700, Vol. 71, no 19, p. 4115-4118Article in journal (Refereed)
    Abstract [en]

    An extremely simple design has been developed for producing durable sheathless electrospray emitters that give highly stable electrospray for unlimited lifetimes. The emitters can be fashioned from any style fused-silica capillary and are ideally suited

  • 3.
    Barnidge, DR
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Nilsson, S
    Markides, KE
    Rapp, H
    Hjort, K
    Metallized sheathless electrospray emitters for use in capillary electrophoresis orthogonal time-of-flight mass spectrometry1999In: RAPID COMMUNICATIONS IN MASS SPECTROMETRY, ISSN 0951-4198, Vol. 13, no 11, p. 994-1002Article in journal (Refereed)
    Abstract [en]

    Chromiun-gold coated fused silica emitters for electrospray ionization have been fabricated with lifetimes upwards of 100 hours. The coating on these emitters is extremely durable withstanding electrical discharges, abrasion and mechanical stress, Usable

  • 4. Berglof, T
    et al.
    Jonsall, G
    Markides, KE
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Selectivity in supercritical fluid extraction: Recovery of pesticides from model matrices1999In: JOURNAL OF CHROMATOGRAPHIC SCIENCE, ISSN 0021-9665, Vol. 37, no 10, p. 400-406Article in journal (Refereed)
  • 5.
    Broadbent, JK
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Martincigh, BS
    Raynor, MW
    Salter, LF
    Moulder, R
    Sjoberg, P
    Markides, KE
    Capillary supercritical fluid chromatography combined with atmospheric pressure chemical ionisation mass spectrometry for the investigation of photoproduct formation in the sunscreen absorber 2-ethylhexyl-p-methoxycinnamate1996In: JOURNAL OF CHROMATOGRAPHY A, ISSN 0021-9673, Vol. 732, no 1, p. 101-110Article in journal (Refereed)
    Abstract [en]

    The photoproducts formed on ultraviolet irradiation of the sunscreen absorber trans-2-ethylhexyl-p-methoxycinnamate, were separated and characterised using a new combined technique, capillary supercritical fluid chromatography-atmospheric pressure chemic

  • 6.
    Bylund, D
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Danielsson, R
    Markides, KE
    Peak purity assessment in liquid chromatography-mass spectrometry2001In: JOURNAL OF CHROMATOGRAPHY A, ISSN 0021-9673, Vol. 915, no 1-2, p. 43-52Article in journal (Refereed)
    Abstract [en]

    Fixed-size moving window evolving factor analysis and base peak chromatograms have been used for peak purity detection in data generated with LC-MS. The two methods were evaluated with both real and simulated data and were found to be fast and complementa

  • 7.
    Forngren, BH
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Samskog, J
    Gustavsson, SA
    Tyrefors, N
    Markides, KE
    Langstrom, B
    Reversed-phase ion-pair chromatography coupled to electrospray ionisation mass spectrometry by on-line removal of the counter-ions1999In: JOURNAL OF CHROMATOGRAPHY A, ISSN 0021-9673, Vol. 854, no 1-2, p. 155-162Article in journal (Refereed)
    Abstract [en]

    A strong anion-exchanger was used as a trapping column to perform on-line coupling of ion-pair chromatography with electrospray ionisation mass spectrometry. Ion-pairing reagents were used to retain polar analytes of low molecular mass away from the solv

  • 8.
    Fridstrom, A
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Nyholm, L
    Netscher, T
    Walther, W
    Lundell, N
    Markides, KE
    Neutral cyclodextrins as chiral agents for enantiomeric separations of chromanes in capillary electrophoresis1997In: CHROMATOGRAPHIA, ISSN 0009-5893, Vol. 44, no 5-6, p. 313-319Article in journal (Refereed)
    Abstract [en]

    Six different cyclodextrins with varying cavity size and rim substitution were used as chiral agents for the enantiomeric separation of eight chromane compounds or analogues using capillary electrophoresis. It is shown that the cyclodextrin type and conc

  • 9.
    Hyllbrant, B
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Tyrefors, N
    Langstrom, B
    Markides, KE
    Packed capillary column liquid chromatography coupled to mass spectrometry by a simple modification of an electrospray interface1999In: JOURNAL OF MICROCOLUMN SEPARATIONS, ISSN 1040-7685, Vol. 11, no 5, p. 353-358Article in journal (Refereed)
    Abstract [en]

    When packed capillary columns are coupled to electrospray mass spectrometry, care must be taken to reduce the dead volumes of the detector connections. In this work, the coupling between the column and the detector was made with a 20-mu m i fused silica

  • 10.
    Hyllbrant, B
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Tyrefors, N
    Markides, KE
    Langstrom, B
    On the use of liquid chromatography with radio- and ultraviolet absorbance detection coupled to mass spectrometry for improved sensitivity and selectivity in determination of specific radioactivity of radiopharmaceuticaIs1999In: JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS, ISSN 0731-7085, Vol. 20, no 3, p. 493-501Article in journal (Refereed)
    Abstract [en]

    Pneumatically assisted electrospray mass spectrometry was evaluated as a complementary detection technique to UV absorbance, for determination of specific radioactivity of tracer molecules to be used in positron emission tomography. Tracers labelled with

  • 11.
    Jacobson, GB
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Markides, KE
    Langstrom, B
    Supercritical fluid synthesis and on-line preparative supercritical fluid chromatography of C-11-labelled compounds in supercritical ammonia1997In: ACTA CHEMICA SCANDINAVICA, ISSN 0904-213X, Vol. 51, no 3, p. 418-425Article in journal (Refereed)
    Abstract [en]

    An automated supercritical fluid synthesis (SFS) system, designed for reaction and on-line preparative supercritical fluid chromatography (SFC) of C-11-labelled (t(1/2) = 20.3 min) compounds in supercritical ammonia, is described. The synthesis and on-li

  • 12.
    Jacobson, GB
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Moulder, R
    Lu, L
    Bergstrom, M
    Markides, KE
    Langstrom, B
    Supercritical fluid extraction of C-11-labeled metabolites in tissue using supercritical ammonia1997In: ANALYTICAL CHEMISTRY, ISSN 0003-2700, Vol. 69, no 3, p. 275-280Article in journal (Refereed)
    Abstract [en]

    Supercritical fluid extraction (SFE) of C-11-labeled tracer compounds and their metabolites from biological tissue was performed using supercritical ammonia in an attempt to develop a rapid extraction procedure that allowed subsequent analysis of the lab

  • 13.
    Jacobson, GB
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Westerberg, G
    Markides, KE
    Langstrom, B
    Synthesis of C-11-labeled guanidines in supercritical ammonia1996In: JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, ISSN 0002-7863, Vol. 118, no 29, p. 6868-6872Article in journal (Refereed)
    Abstract [en]

    The synthesis of ten C-11-labeled aromatic and aliphatic guanidines in supercritical ammonia is described. The corresponding amines were first converted into cyanamides by reactions with [C-11]cyanogen bromide. The aliphatic amines gave high yields of C-

  • 14.
    Juvancz, Z
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Jicsinszky, L
    Markides, KE
    Phosphated cyclodextrins as new acidic chiral additives for capillary electrophoresis1997In: JOURNAL OF MICROCOLUMN SEPARATIONS, ISSN 1040-7685, Vol. 9, no 8, p. 581-589Article in journal (Refereed)
    Abstract [en]

    The study describes the use of alpha,beta, and gamma phosphated cyclodextrins (CDs) for chiral separation by capillary electrophoresis (CE). A systematic study was performed to establish the effect of such variables as the type and concentration of chira

  • 15.
    Juvancz, Z
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Markides, KE
    Jicsinszky, L
    Chiral analysis of metoprolol and its by-products by capillary electrophoresis1999In: JOURNAL OF MICROCOLUMN SEPARATIONS, ISSN 1040-7685, Vol. 11, no 10, p. 716-722Article in journal (Refereed)
    Abstract [en]

    The enantiomers of metoprolol, a frequently used beta-blocker, have different physiological effects, which makes their chiral separation necessary. The separation of the main product from its by-products and their chiral separation were also aims of this

  • 16.
    Juvancz, Z
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Markides, KE
    Jicsinszky, L
    Enantiomer separation of disopyramide with capillary electrophoresis using various cyclodextrins1997In: ELECTROPHORESIS, ISSN 0173-0835, Vol. 18, no 6, p. 1002-1006Article in journal (Refereed)
    Abstract [en]

    Enantiomers of disopyramide display different biological actions, and therefore chiral selective analysis is necessary. Fifteen different cyclodextrins (CDs) and CD derivatives were tested as capillary electrophoresis (CE) additives for the chiral separa

  • 17.
    Juvancz, Z
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Markides, KE
    Jicsinszky, L
    Ivanyi, R
    Chiral selective separation of tocainide by capillary electrophoresis using various cyclodextrin derivatives2001In: JOURNAL OF MICROCOLUMN SEPARATIONS, ISSN 1040-7685, Vol. 13, no 2, p. 62-68Article in journal (Refereed)
    Abstract [en]

    Chiral separation of tocainide, an antiarrythmic agent, was solved using the capillary electrophoresis method. Fifteen types of cyclodextrins were tried as chiral selective buffer additives, and baseline separation was achieved with five of them. The vari

  • 18. Juvancz, Z
    et al.
    Markides, KE
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Rouse, CA
    Jones, K
    Tarbet, BJ
    Bradshaw, JS
    Lee, ML
    A polymeric high resolution Pirkle-type chiral stationary phase for GC and SFC1998In: Enantomier, ISSN 1024-2430, Vol. 3, no 2, p. 89-94Article in journal (Refereed)
    Abstract [en]

    A chiral stationary phase with a silicone backbone and substituted side chains of (S)-N-1-(1-naphthyl)-4-propyloxybenzamide substitution has been introduced for open tubular column GC and SFC. The stationary phase has a broad temperature working range 20-280 degrees C), and provides highly efficient columns (> 3000 plates/meter). One of the key interactions for selectivity is the pi-pi interaction, but the stationary phase can also be used to separate enantiomers without pi electrons. The phase can be used to separate a broad range of compounds, which is demonstrated by the separation of enantiomeric compounds having aromatic rings, amino acid and terpenic alcohol groups. This stationary phase expands the use of Pirkle phases into the field of open tubular column chromatography.

  • 19.
    Koivisto, P
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Danielsson, R
    Markides, KE
    Factors affecting the preparation of packed capillary columns in supercritical carbon dioxide media1997In: JOURNAL OF MICROCOLUMN SEPARATIONS, ISSN 1040-7685, Vol. 9, no 2, p. 97-103Article in journal (Refereed)
    Abstract [en]

    In this study, packed capillary columns were prepared using supercritical carbon dioxide as a packing carrier. A factorial design was used to examine the effect that four selected factors have on the packing performance. The investigated factors were: 1)

  • 20.
    Matysik, FM
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Nyholm, L
    Markides, KE
    Comparison of mu m and mm sized disk electrodes for end-column electrochemical detection in capillary electrophoresis1999In: FRESENIUS JOURNAL OF ANALYTICAL CHEMISTRY, ISSN 0937-0633, Vol. 363, no 3, p. 231-235Article in journal (Refereed)
    Abstract [en]

    End-column electrochemical detection based on either the use of a 25 mu m microdisk electrode or a 0.5 mm macrodisk electrode has been compared with respect to performance and influence on non-aqueous capillary electrophoretic separations. Despite the mu

  • 21.
    Nilsson, S
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Markides, KE
    On-column conductive coating for thermolabile columns used in CZE-sheathless electrospray ESI-MS2000In: RAPID COMMUNICATIONS IN MASS SPECTROMETRY, ISSN 0951-4198, Vol. 14, no 1, p. 6-11Article in journal (Refereed)
    Abstract [en]

    A simple and very mild approach for the application of a conductive layer for sheathless electrospray has been developed. A modified 'fairy dust' method is employed in which 2 mu m gold particles are applied by a thin layer of silicone on shaped tips. Thi

  • 22.
    Nyholm, LM
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Markides, KE
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Column preparation for reversed-phase high-temperature open tubular column liquid chromatography1998In: JOURNAL OF CHROMATOGRAPHY A, ISSN 0021-9673, Vol. 813, no 1, p. 11-20Article in journal (Refereed)
    Abstract [en]

    A method for the preparation of stable reversed-phase columns for high temperature open tubular column liquid chromatography (HT-OT-LC) has been developed and the effect of covalent bonding of the stationary phase to a covalently bonded deactivation laye

  • 23.
    Nyholm, LM
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Sjoberg, PJR
    Markides, KE
    High-temperature open tubular liquid chromatography coupled to atmospheric pressure chemical ionisation mass spectrometry1996In: JOURNAL OF CHROMATOGRAPHY A, ISSN 0021-9673, Vol. 755, no 2, p. 153-164Article in journal (Refereed)
    Abstract [en]

    A micro heated nebuliser interface was constructed and used for coupling of open tubular liquid chromatography at 150 degrees C to atmospheric pressure chemical ionisation mass spectrometry. For the chromatography, 50 mu m I.D. columns were utilised at a

  • 24.
    Petersson, U
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Markides, KE
    Stability and purity of low-polarity adsorbents for coupled supercritical fluid extraction-supercritical fluid chromatography-flame ionization detection1996In: JOURNAL OF CHROMATOGRAPHY A, ISSN 0021-9673, Vol. 734, no 2, p. 311-318Article in journal (Refereed)
    Abstract [en]

    Several adsorbent materials have been evaluated for their purity and stability when used and reused in on-line solid-phase adsorption (SPA)-supercritical fluid extraction (SFE)-supercritical fluid chromatography (SFC) with neat carbon dioxide as mobile p

  • 25. Sandberg, A
    et al.
    Markides, KE
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Heldin, E
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Lasalocid adsorbed on porous graphitic carbon as a chiral selector, in capillary liquid chromatography1998In: JOURNAL OF CHROMATOGRAPHY A, ISSN 0021-9673, Vol. 828, no 1-2, p. 149-156Article in journal (Refereed)
    Abstract [en]

    Lasalocid, which has high affinity for porous graphitic carbon (PGC), has been dynamically adsorbed onto PGC and used in capillary liquid chromatography. Several enantiomers of amines, acids, amino acids and alcohols have been separated on this system an

  • 26.
    Selditz, U
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Nilsson, S
    Barnidge, D
    Markides, KE
    ESI/TOF-MS detection for microseparation techniques1999In: CHIMIA, ISSN 0009-4293, Vol. 53, no 10, p. 506-510Article in journal (Refereed)
    Abstract [en]

    The choice of electrospray ionisation/time-of-flight mass spectrometry (ESI/TOF-MS) as mass analyser for combination with microseparation techniques, such as mu LC, CE and CEC, may be recommended due to the features that present-day TOF-MS instruments ha

  • 27.
    Senorans, FJ
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Markides, KE
    Nyholm, L
    Determination of tocopherols and vitamin A in vegetable oils using packed capillary column supercritical fluid chromatography with electrochemical detection1999In: JOURNAL OF MICROCOLUMN SEPARATIONS, ISSN 1040-7685, Vol. 11, no 5, p. 385-391Article in journal (Refereed)
    Abstract [en]

    A recently developed microelectrochemical detector for packed capillary column supercritical fluid chromatography (pcSFC) has been applied to determine nanogram amounts of tocopherols and vitamin A in vegetable oil samples. With this procedure, no remova

  • 28.
    Sjoberg, PJR
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Bokman, CF
    Bylund, D
    Markides, KE
    A method for determination of ion distribution within electrosprayed droplets2001In: ANALYTICAL CHEMISTRY, ISSN 0003-2700, Vol. 73, no 1, p. 23-28Article in journal (Refereed)
    Abstract [en]

    A simplified method for determination of ion distribution within electrospray ionization droplets has been developed, The method is based on an electrospray ionization mass spectrometry equilibrium partitioning model recently developed by Enke (Enke, C. G

  • 29.
    Sjoberg, PJR
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Bokman, CF
    Bylund, D
    Markides, KE
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Factors influencing the determination of analyte ion surface partitioning coefficients in electrosprayed droplets2001In: JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY, ISSN 1044-0305, Vol. 12, no 9, p. 1002-1010Article in journal (Refereed)
    Abstract [en]

    The observed response in mass spectrometry utilizing electrospray as a sample introduction technique can be affected by a number of factors. In this study a series of two-electrolyte systems was investigated and the mass spectrometric responses were model

  • 30.
    Sjoberg, PJR
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Markides, KE
    Capillary column supercritical fluid chromatography-atmospheric pressure ionisation mass spectrometry - Interface performance of atmospheric pressure chemical ionisation and electrospray ionisation1999In: JOURNAL OF CHROMATOGRAPHY A, ISSN 0021-9673, Vol. 855, no 1, p. 317-327Article in journal (Refereed)
    Abstract [en]

    A supercritical fluid chromatography interface probe for atmospheric pressure ionisation mass spectrometry (API-MS) with the advantage of convenient switch between ionisation modes [atmospheric pressure chemical ionisation (APCI) and electrospray ionisat

  • 31.
    Sjoberg, PJR
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Markides, KE
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Energy-resolved collision-induced dissociation atmospheric pressure chemical ionization mass spectrometry of constitutional and stereo steroid isomers1998In: JOURNAL OF MASS SPECTROMETRY, ISSN 1076-5174, Vol. 33, no 9, p. 872-883Article in journal (Refereed)
    Abstract [en]

    Energy-resolved mass spectra were recorded by controlled up-front collision-induced dissociation (CID) or conventional CID tandem mass spectrometry. Differentiation between constitutional isomers and stereoisomers of hydroxysteroids was studied using atm

  • 32.
    Sjoberg, PJR
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Markides, KE
    New supercritical fluid chromatography interface probe for electrospray and atmospheric pressure chemical ionization mass spectrometry1997In: JOURNAL OF CHROMATOGRAPHY A, ISSN 0021-9673, Vol. 785, no 1-2, p. 101-110Article in journal (Refereed)
    Abstract [en]

    A new supercritical fluid chromatography interface probe has been constructed for atmospheric pressure ionization mass spectrometry (API-MS). The use of API-MS effectively separates the ionization and mass analysis regions. Furthermore, a sheath-liquid f

  • 33.
    Sjoberg, PJR
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Nyholm, L
    Markides, KE
    Characterization of the atmospheric pressure ionization mass spectrometric process obtained using a fused-silica emitter with the high voltage applied upstream2000In: JOURNAL OF MASS SPECTROMETRY, ISSN 1076-5174, Vol. 35, no 3, p. 330-336Article in journal (Refereed)
    Abstract [en]

    The atmospheric pressure ionization process obtained when a mixture of methanol and water (90:10, v/v) also containing 50 mu m sodium hydroxide is dispersed from a fused-silica emitter was studied, A combination of a high electric held and a nebulizer gas

  • 34.
    Stefansson, M
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Sjoberg, PJR
    Markides, KE
    Regulation of multimer formation in electrospray mass spectrometry1996In: ANALYTICAL CHEMISTRY, ISSN 0003-2700, Vol. 68, no 10, p. 1792-1797Article in journal (Refereed)
    Abstract [en]

    Extensive multimer formation of small and uncharged analytes was observed in electrospray mass spectrometry. The concentration-dependent aggregation behavior, including species up to tetramers, resulted in highly nonlinear calibration curves, For some an

  • 35.
    Swart, R
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Koivisto, P
    Markides, KE
    Capillary solid-phase extraction-tandem mass spectrometry for fast quantification of free concentrations of tolterodine and two metabolites in ultrafiltered plasma samples1999In: JOURNAL OF CHROMATOGRAPHY B, ISSN 0378-4347, Vol. 736, no 1-2, p. 247-253Article in journal (Refereed)
    Abstract [en]

    A capillary solid-phase extraction (SPE) system has been coupled directly to electrospray tandem mass spectrometry for quantification of free tolterodine and metabolite concentrations in plasma. The unbound fraction of these compounds was obtained by ultr

  • 36. Swart, R
    et al.
    Koivisto, P
    Markides, KE
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Column switching in capillary liquid chromatography tandem mass spectrometry for the quantitation of pg/ml concentrations of the free basic drug tolterodine and its active 5-hydroxymethyl metabolite in microliter volumes of plasma1998In: JOURNAL OF CHROMATOGRAPHY A, ISSN 0021-9673, Vol. 828, no 1-2, p. 209-218Article in journal (Refereed)
    Abstract [en]

    A capillary column switching system was developed for the determination of low, unbound concentrations of the basic drug tolterodine and its active 5-hydroxymethyl (5-HM) metabolite in human plasma. Free concentrations of tolterodine and 5-HM at pM and n

  • 37.
    Waldeback, M
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Jansson, C
    Senorans, FJ
    Markides, KE
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Accelerated solvent extraction of the antioxidant Irganox 1076 in linear low density polyethylene (LLDPE) granules before and after gamma-irradiation1998In: ANALYST, ISSN 0003-2654, Vol. 123, no 6, p. 1205-1207Article in journal (Refereed)
    Abstract [en]

    To achieve effective and reproducible extractions of the antioxidant Irganox 1076 from linear low density polyethylene (LLDPE) components at reduced time and cost, the accelerated solvent extraction (ASE) technique was evaluated with solvent composition

  • 38.
    Wallenborg, SR
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Markides, KE
    Nyholm, L
    A microelectrochemical detector for use at low linear velocities in capillary column systems1997In: ANALYTICA CHIMICA ACTA, ISSN 0003-2670, Vol. 344, no 1-2, p. 77-85Article in journal (Refereed)
    Abstract [en]

    An end-column microelectrochemical detector, based on a 25 mu m platinum electrode, was used in miniaturised flow and separation systems, at linear mobile phase velocities below 0.1 cm s(-1) (i.e. a volumetric flow of a few mu l min(-1) for a 200 mu m i

  • 39.
    Wallenborg, SR
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Markides, KE
    Nyholm, L
    Development of an amperometric detector for packed capillary column supercritical fluid chromatography1997In: ANALYTICAL CHEMISTRY, ISSN 0003-2700, Vol. 69, no 3, p. 439-445Article in journal (Refereed)
    Abstract [en]

    Amperometric detection at a naked platinum microelectrode is shown to be compatible with pressure-programmed packed capillary column supercritical fluid chromatography (SFC) using carbon dioxide modified with as little as 1% acetonitrile, Amperometric de

  • 40.
    Wallenborg, SR
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Markides, KE
    Nyholm, L
    Oxidative and reductive amperometric detection of phenolic and nitroaromatic compounds in packed capillary column supercritical fluid chromatography1997In: JOURNAL OF CHROMATOGRAPHY A, ISSN 0021-9673, Vol. 785, no 1-2, p. 121-128Article in journal (Refereed)
    Abstract [en]

    Oxidative and reductive amperometric detection of phenols, nitroaromatic compounds and a cyclic ketone is demonstrated in packed capillary column supercritical fluid chromatography (SFC). The detection was performed in combination with isobaric, as well

1 - 40 of 40
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