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Adlard ER, Myers P, Wilson ID, Wilson L, Ettre LS. Book reviews. Chromatographia 2001. [DOI: 10.1007/bf02492198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Martin PD, Wilson TD, Wilson ID, Jones GR. An unexpected selectivity of a propranolol-derived molecular imprint for tamoxifen. Analyst 2001; 126:757-9. [PMID: 11445932 DOI: 10.1039/b102424h] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
During the evaluation of molecular imprinted polymers (MIPs) prepared against the drug tamoxifen a propranolol-derived MIP was used as a positive control. Surprisingly the propranolol-derived MIP showed considerable selectivity towards tamoxifen, and was indeed much more selective than the MIP prepared using tamoxifen as the imprint molecule. The consequences of this unexpected, cross reactivity for the use of MIPs in analytical chemistry is discussed.
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Coen M, Lindon JC, Gavaghan C, Holmes E, Humpfer E, Wilson ID, Stanley PD, Nicholson JK. Investigation of water environments in a C18 bonded silica phase using 1H magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy. Analyst 2001; 126:548-50. [PMID: 11394288 DOI: 10.1039/b102347k] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
High resolution 1H magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectra have been obtained on typical C18 bonded silicas used in chromatographic solid-phase extraction separations. It has been shown for the first time that water molecules distributed in distinct physico-chemical environments within the chromatographic system can be detected directly using a simple 1H MAS NMR measurement. The resonances assigned to water protons in differing physico-chemical environments have distinct chemical shifts, line widths, relaxation times (T1 and T2) and also exhibit temperature dependent coalescence behaviour. This novel MAS approach may lead to a better understanding of the environments of other analytes in mixtures during such separations.
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Gavaghan CL, Nicholson JK, Connor SC, Wilson ID, Wright B, Holmes E. Directly coupled high-performance liquid chromatography and nuclear magnetic resonance spectroscopic with chemometric studies on metabolic variation in Sprague--Dawley rats. Anal Biochem 2001; 291:245-52. [PMID: 11401298 DOI: 10.1006/abio.2000.5034] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We report here the first combined use of NMR-PR (pattern recognition) analysis and directly coupled HPLC--NMR analysis to identify metabolic subpopulations in normal laboratory animals and their discriminating endogenous urinary biomarkers. Urine samples obtained from control Sprague-Dawley rats (n = 68) were analyzed using (1)H NMR spectroscopy and principal components (PC) analysis to investigate physiological variability. Two distinct subpopulations of animals were classified based on metabolite excretion profiles. Analysis of the PC loadings established the spectral regions that were responsible for classification of the subpopulations and was used to direct the identification of biomarkers using a directly coupled HPLC--NMR analysis. One population had low urinary hippurate levels together with an increased concentration of 3-(3-hydroxyphenyl)propionic acid (3-HPPA)and 3-hydroxycinnamic acid (3-HCA). The other subpopulation excreted high levels of hippurate. Thus, we report the bimodal occurrence of hippuric acid and chlorogenic acid metabolites in a genetically homogeneous population of rats maintained under identical conditions, which may have significance in relation to the understanding of the consequences of biochemical variation in animals used for drug toxicity testing.
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Nicholson JK, Lindon JC, Scarfe GB, Wilson ID, Abou-Shakra F, Sage AB, Castro-Perez J. High-performance liquid chromatography linked to inductively coupled plasma mass spectrometry and orthogonal acceleration time-of-flight mass spectrometry for the simultaneous detection and identification of metabolites of 2-bromo-4-trifluoromethyl. Anal Chem 2001; 73:1491-4. [PMID: 11321299 DOI: 10.1021/ac001085p] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The use of HPLC coupled to inductively coupled plasma mass spectrometry (ICPMS) and orthogonal acceleration time-of-flight (oa-TOF) for the profiling, identification, and quantification of metabolites in rat urine following the administration of 2-bromo-4-trifluoromethylacetanilide is described. The metabolites present in the sample were separated by reversed-phase gradient chromatography with UV-diode array detection. The bulk of the eluent (90%) from the UV detector was directed to an ICPMS where bromine-containing metabolites were detected and quantified using ICPMS. The minor portion of the eluent (10%) was taken for oa-TOFMS for identification. By these means, the metabolites were identified as sulfate and glucuronide conjugates of a ring hydroxy-substituted metabolite, a N-sulfate, a N-hydroxylamine glucuronide, and N- and N-hydroxyglucuronides.
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Chen GP, Wilson ID, Kim SH, Grierson D. Inhibiting expression of a tomato ripening-associated membrane protein increases organic acids and reduces sugar levels of fruit. PLANTA 2001; 212:799-807. [PMID: 11346954 DOI: 10.1007/s004250000431] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Tomato (Lycopersicon esculentum Mill.) ripening-associated membrane protein (TRAMP) is a channel protein of the membrane intrinsic protein (MIP) class encoded by the cDNA clone pNY507 [R.G. Fray et al. (1994) Plant Mol Biol 24: 539-543]. It has been suggested that these proteins encode water channels or aquaporins. TRAMP mRNA accumulated in all tomato tissues tested and was elevated in fruit during post-anthesis development and again during ripening. Transgenic plants that constitutively expressed a TRAMP antisense RNA sequence were generated with a 94% reduction of endogenous TRAMP mRNA in fruit. They showed no obvious phenotype that could be associated with gross perturbation of water relations, but ripening fruit of these plants showed marked alterations in the normal pattern of accumulation of both organic acids and sugars. At the onset and during ripening, levels of the organic acids L-malate and citrate were significantly elevated while levels of D[+]-glucose and D[+]-fructose were reduced. Additional transgenic lines were generated with reduced TRAMP mRNA, and the phenotype of increased acids and reduced sugars during fruit maturation and ripening was shown to be reproducible and stably inherited. Fruit of plants that over-expressed TRAMP mRNA showed no significant alteration in the sugars or acids investigated. These results suggest a role for TRAMP in the movement of solutes between cell compartments.
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Louden D, Handley A, Taylor S, Lenz E, Miller S, Wilson ID, Sage A, Lafont R. Spectroscopic characterisation and identification of ecdysteroids using high-performance liquid chromatography combined with on-line UV--diode array, FT-infrared and 1H-nuclear magnetic resonance spectroscopy and time of flight mass spectrometry. J Chromatogr A 2001; 910:237-46. [PMID: 11261718 DOI: 10.1016/s0021-9673(00)01204-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
A prototype multiply hyphenated reversed-phase HPLC system has been applied to the analysis of a mixture of pure ecdysteroids and an ecdysteroid-containing plant extract. Characterisation was achieved via a combination of diode array UV, 1H NMR, FT-IR spectroscopy and time of flight (TOF) mass spectrometry. This combination of spectrometers allowed the collection of UV, 1H NMR, IR and mass spectra for a mixture of pure standards enabling almost complete structural characterisation to be performed. The technique was then applied to a partially purified plant extract in which 20-hydroxyecdysone and polypodine B were identified despite incomplete chromatographic resolution and the presence of co-chromatographing interferents. The experimental difficulties in the use of such a systems for these analytes are described.
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Wilson ID, Bramwell SP, Hollins GW. A randomized trial comparing bladder infusion with standard catheter removal after transurethral resection of the prostate. BJU Int 2000; 86:993-5. [PMID: 11119091 DOI: 10.1046/j.1464-410x.2000.00963.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To examine the effect of bladder infusion before catheter removal on patients' readiness for discharge and the day of discharge after transurethral resection of the prostate (TURP). PATIENTS AND METHODS The study comprised 75 consecutive patients undergoing TURP who were randomized to either have their catheter removed in the standard manner (38 patients), or to undergo bladder infusion before a trial of voiding (ToV) on the second day after TURP (37 patients). RESULTS In those undergoing bladder infusion, seven (19%) patients were discharged on the same day as their ToV, compared with five (13%) in the standard group. Of the 75 patients, 15 (68%) were discharged by the third day after TURP whether or not the bladder had been filled. In the infusion group, 23 (62%) were ready for discharge on the same day as their TOV, compared with only 14 (37%) in the standard group (P < 0.05). CONCLUSION Bladder infusion before a ToV after TURP significantly increases the rate of readiness for discharge, allowing an early decision to discharge on the second day in a large proportion of patients.
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Gavaghan CL, Holmes E, Lenz E, Wilson ID, Nicholson JK. An NMR-based metabonomic approach to investigate the biochemical consequences of genetic strain differences: application to the C57BL10J and Alpk:ApfCD mouse. FEBS Lett 2000; 484:169-74. [PMID: 11078872 DOI: 10.1016/s0014-5793(00)02147-5] [Citation(s) in RCA: 230] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
As the human genome sequencing projects near completion, there is an active search for technologies that can provide insights into the genetic basis for physiological variation and interpreting gene expression in terms of phenotype at the whole organism level in order to understand the pathophysiology of disease. We present a novel metabonomic approach to the investigation of genetic influences on metabolic balance and metabolite excretion patterns in two phenotypically normal mouse models (C57BL10J and Alpk:ApfCD). Chemometric techniques were applied to optimise recovery of biochemical information from complex (1)H NMR urine spectra and to determine metabolic biomarker differences between the two strains. Differences were observed in tricarboxylic acid cycle intermediates and methylamine pathway activity. We suggest here a new 'metabotype' concept, which will be of value in relating quantitative physiological and biochemical data to both phenotypic and genetic variation in animals and man.
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Lindon JC, Nicholson JK, Wilson ID. Directly coupled HPLC-NMR and HPLC-NMR-MS in pharmaceutical research and development. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 2000; 748:233-58. [PMID: 11092602 DOI: 10.1016/s0378-4347(00)00320-0] [Citation(s) in RCA: 164] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The methodology for the direct coupling of HPLC with NMR spectroscopy and the simultaneous double coupling of HPLC with NMR and mass spectrometry (MS) is described. Indications of the necessary technical developments to achieve this are given, and the applications of these new techniques to studies of pharmaceutical relevance are reviewed. These include studies of combinatorial chemistry libraries, synthetic chemical impurities, characterisation of drug mixtures, identification of natural products of possible pharmaceutical interest and identification of xenobiotic metabolites in human, animal and in vitro systems. In addition, HPLC-NMR has been used to investigate xenobiotic metabolite reactivity. Finally, the potential future directions of the techniques are discussed.
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Scarfe GB, Clayton E, Wilson ID, Nicholson JK. Identification and quantification of metabolites of 2,3,5,6-tetrafluoro-4-trifluoromethylaniline in rat urine using 19F nuclear magnetic resonance spectroscopy, high-performance liquid chromatography-nuclear magnetic resonance spectroscopy and high-performance liquid chromatography-mass spectrometry. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 2000; 748:311-9. [PMID: 11092607 DOI: 10.1016/s0378-4347(00)00321-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The urinary excretion profile and identity of the metabolites of 2,3,5,6-tetrafluoro-4-triflouromethylaniline, following i.p. administration to the rat at 50 mg kg(-1), were determined using a combination of 19F-NMR, HPLC-NMR and HPLC-MS. A total of 38% of the dose was eliminated in the urine as five metabolites. The major routes of metabolism were N-glucuronidation, sulfation and oxidation with a significant amount of metabolic defluorination to give a number of ortho-ring hydroxylated metabolites. The oxidised metabolites were excreted as glucuronide and/or sulfate conjugates.
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Wilson ID. Multiple hyphenation of liquid chromatography with nuclear magnetic resonance spectroscopy, mass spectrometry and beyond. J Chromatogr A 2000; 892:315-27. [PMID: 11045496 DOI: 10.1016/s0378-4347(00)00071-2] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The advent of sensitive and reliable HPLC-NMR and HPLC-MS systems has revolutionised the identification of compounds eluting from chromatographic systems. More recently systems have been described wherein both NMR and MS are used together to provide an immensely powerful means of characterising compounds in chromatographic eluents. Here the construction and application of combined HPLC-NMR-MS systems to the analysis of mixtures of pharmaceuticals, drug metabolites in biological fluids and natural products in plant extracts is reviewed. In addition preliminary work with alternative systems such as HPLC-UV-NMR-FTIR-MS is highlighted and the prospects for such complex systems considered.
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Louden D, Handley A, Taylor S, Lenz E, Miller S, Wilson ID, Sage A. Reversed-phase high-performance liquid chromatography combined with on-line UV diode array, FT infrared, and 1H nuclear magnetic resonance spectroscopy and time-of-flight mass spectrometry: application to a mixture of nonsteroidal antiinflammatory drugs. Anal Chem 2000; 72:3922-6. [PMID: 10959983 DOI: 10.1021/ac000204y] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A prototype multiply hyphenated system has been applied to the analysis of a mixture of nonsteroidal antiinflammatory drugs separated by reversed-phase HPLC. Characterization of the model NSAIDs was achieved via a combination of diode array UV, 1H NMR, FT-IR spectroscopy, and time-of-flight mass spectrometry. This combination of spectrometers allowed the collection of UV, 1H NMR, IR, and mass spectra together with atomic composition data enabling almost complete structural characterization to be performed.
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Martin P, Wilson ID, Jones GR. Optimisation of procedures for the extraction of structural analogues of propranolol with molecular imprinted polymers for sample preparation. J Chromatogr A 2000; 889:143-7. [PMID: 10985546 DOI: 10.1016/s0021-9673(00)00570-7] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
A propranolol-derived molecular imprinted polymer (MIP) was prepared using methacrylic acid as monomer and ethylene glycol dimethacrylate as cross-linker. The extraction properties of five compounds structurally related to propranolol were assessed on the MIP and on a blank polymer made under the same conditions but in the absence of an imprint molecule. Using application from aqueous solution with methanol-water-triethylamine (TEA)-based solvents for elution (i.e. reversed-phase conditions) the MIP showed only marginal selectivity for the compounds on the MIP compared to the blank. Despite the limited selectivity there did appear to be a relationship between structure of the compound (relative to propranolol) and the extent of selective retention. Application of the compounds in toluene with elution using toluene-TEA or toluene-trifluoroacetic acid resulted in the MIP showing dramatically enhanced retention and selectivity of the compounds on the MIP compared to the blank. The enhanced selectivity for extraction on to the MIP relative to the blank, for all compounds using normal-phase solvents seem to be a class effect as there was no apparent relationship between compound structure and retention.
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Smith RM, Chienthavorn O, Saha S, Wilson ID, Wright B, Taylor SD. Selective deuterium exchange during superheated heavy water chromatography-nuclear magnetic resonance spectroscopy-mass spectrometry of sulfonamides. J Chromatogr A 2000; 886:289-95. [PMID: 10950296 DOI: 10.1016/s0021-9673(00)00493-3] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Superheated deuterium oxide has been investigated as an eluent for reversed-phase HPLC on a polystyrene-divinylbenzene column with UV, 1H NMR and MS detection using a series of sulfonamides as model compounds. In the course of these studies, a selective, specific and efficient deuteration of the methyl groups on a pyrimidine ring was observed during chromatography of certain of the sulfonamides. The potential of this methodology for producing deuterium-labelled compounds from substances bearing suitable substituents is considered. The utility of HPLC-NMR-MS as a means for studying on-column reactions is discussed.
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Scarfe GB, Lindon JC, Nicholson JK, Martin P, Wright B, Taylor S, Lenz E, Wilson ID. Investigation of the metabolism of 14C/13C-practolol in rat using directly coupled radio-HPLC-NMR-MS. Xenobiotica 2000; 30:717-29. [PMID: 10963062 DOI: 10.1080/00498250050078020] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
1. The metabolic fate of 14C/13C-practolol was investigated using on-line HPLC-NMR-MS following oral administration to rat. The major route of elimination for the radiolabel was via the urine with the principal biotransformation products confirmed as the 2-hydroxy- and 2-hydroxyglucronide metabolites. 2. In addition, futile deacetylation, determined by the replacement of 13C-labelled acetyl groups with endogenous 12C-acetyls accounted for approximately 7-10% of the urinary metabolites, corresponding to approximately 5% of the dose undergoing N-deacetylation. 3. Evidence for chiral metabolism was sought via NMR of isolated metabolites using beta-cyclodextrin as a chiral shift agent. Practolol was excreted as a racemate. However, some enantioselective metabolism/excretion had occurred as the hydroxy- and hydroxyglucuronide were not excreted as racemic mixtures. 4. Directly coupled radio-HPLC-NMR-MS is extremely effective for the identification of the metabolites of radiolabelled xenobiotics in urine samples.
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Blackledge CA, Partridge EA, Wilson ID, Nicholson JK. The metabolism and excretion of [14c] 2- and 4-chlorobenzoic acids in the rat. J Pharm Biomed Anal 2000; 22:1023-8. [PMID: 10857571 DOI: 10.1016/s0731-7085(00)00295-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The metabolic fate of [14C]-labelled 2 and 4-chlorobenzoic acids (2- and 4-CBA) has been determined in the rat following intraperitoneal (i.p.) administration at 100 mg/kg to male rats. The major route of elimination for both 2-and 4-CBA was urine with > 80%, of the dose recovered in the initial 0-24 h after administration. Glycine conjugation was found to be the dominant metabolic fate for both [14C] 2- and 4-CBA however, the position of chloro substitution had a clear effect on the extent of metabolism via this route with ortho substitution reducing the extent of metabolism via this pathway.
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69
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Hennion MC, Penny D, Wilson ID, Adlard ER, Engelhardt H. Book reviews. Chromatographia 2000. [DOI: 10.1007/bf02490805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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70
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Louden D, Handley A, Taylor S, Lenz E, Miller S, Wilson ID, Sage A. Flow injection spectroscopic analysis of model drugs using on-line UV-diode array, FT-infrared and 1H-nuclear magnetic resonance spectroscopy and time-of-flight mass spectrometry. Analyst 2000; 125:927-31. [PMID: 10885057 DOI: 10.1039/b000696n] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A prototype flow injection analysis (FIA) system for the characterisation of compounds via a combination of diode array UV, 1H NMR, FT-IR spectroscopy and time-of-flight (TOF) mass spectrometry has been investigated using a number of pharmaceuticals and related compounds as model compounds. This combination of spectrometers allowed the on-flow collection of UV, 1H NMR, IR and mass spectra together with atomic composition data, enabling almost complete structural characterisation to be performed. Practical detection limits with the current system were in the region of 50 micrograms, however, the use of state of the art spectrometers would result in a significant reduction in the amount of material required.
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Nicholson JK, Lindon JC, Scarfe G, Wilson ID, Abou-Shakra F, Castro-Perez J, Eaton A, Preece S. High-performance liquid chromatography and inductively coupled plasma mass spectrometry (HPLC-ICP-MS) for the analysis of xenobiotic metabolites in rat urine: application to the metabolites of 4-bromoaniline. Analyst 2000; 125:235-6. [PMID: 10820889 DOI: 10.1039/a909494f] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The use of HPLC-ICP-MS for the profiling and quantification of the metabolites of 4-bromoaniline following reversed-phase gradient chromatography is demonstrated. In the 0-8 h post dose sample, which contained the highest concentrations of compound-related material, it was possible to detect at least 16 metabolites of the compound. The methodology described offers the possibility of obtaining metabolite profiles and quantification for drugs and other xenobiotics in biological fluids and excreta without the requirement for radiolabelled tracers.
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Wilson ID. Investigation of a range of stationary phases for the separation of model drugs by HPLC using superheated water as the mobile phase. Chromatographia 2000. [DOI: 10.1007/bf02493117] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Bailey NJ, Cooper P, Hadfield ST, Lenz EM, Lindon JC, Nicholson JK, Stanley PD, Wilson ID, Wright B, Taylor SD. Application of directly coupled HPLC-NMR-MS/MS to the identification of metabolites of 5-trifluoromethylpyridone (2-hydroxy-5-trifluoromethylpyridine) in hydroponically grown plants. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2000; 48:42-46. [PMID: 10637049 DOI: 10.1021/jf990387t] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Directly coupled HPLC-NMR-MS was used to characterize two major metabolites of 5-trifluoromethylpyridone (2-hydroxy-5-trifluoromethylpyridine), a model compound for herbicides, after it had been dosed into hydroponically grown maize plants. The combination of NMR and MS data allowed the identification of both of these metabolites, namely, the N-glucoside and O-malonylglucoside conjugates of the parent pyridone. This work demonstrates the efficiency and the potential application of HPLC-NMR-MS to the investigation of the metabolism of agrochemicals. The work also indicates that combination of the use of hydroponically grown plants and directly coupled HPLC-NMR-MS allows rapid identification of metabolites with little sample preparation.
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Martin P, Wilson ID, Jones GR. Application and elution conditions for the selective elution of analytes from molecular imprinted polymers after extraction from aqueous samples: Application to β-blockers. Chromatographia 2000. [DOI: 10.1007/bf02493113] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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75
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Palmer ME, Tetler LW, Wilson ID. Hydrogen/deuterium exchange using a coaxial sheath-flow interface for capillary electrophoresis/mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2000; 14:808-817. [PMID: 10825020 DOI: 10.1002/(sici)1097-0231(20000515)14:9<808::aid-rcm948>3.0.co;2-p] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The interfacing of capillary electrophoresis (CE) with mass spectrometry (MS) is well established and may be accomplished by use of either a coaxial arrangement or by employing a liquid T-junction. In both these interfaces a make-up flow is introduced. This is required because of the mismatch in flow rates for capillary electrophoresis approximately nL/min and 'true' electrospray approximately 2-10 microL/min. Electrical connectivity may also be established where the liquid flows meet (the introduction of nanospray renders the use of make-up flow unnecessary). Hydrogen/deuterium (H/D) exchange occurs in solution when there are labile hydrogen atoms present in a molecule. The establishment of the presence and the number of such exchangeable hydrogen atoms may be of importance in the identification and differentiation of compounds. It may also be an aid in the structural elucidation of unknown materials. We have investigated the feasibility of carrying out H/D exchange via a CE/MS interface. This involved the addition of D2O to the sheath flow and our preliminary results showing the separations of drug substances, subsequently undergoing exchange, are presented.
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