1
|
|
2
|
Meckley TD, Wagner CM, Luehring MA. Field evaluation of larval odor and mixtures of synthetic pheromone components for attracting migrating sea lampreys in rivers. J Chem Ecol 2012; 38:1062-9. [PMID: 22797851 DOI: 10.1007/s10886-012-0159-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Revised: 05/17/2012] [Accepted: 06/21/2012] [Indexed: 10/28/2022]
Abstract
The sea lamprey, Petromyzon marinus, is a harmful invader of the Laurentian Great Lakes. The odor emitted by larval lampreys resident to streams attracts migrating adults to high quality spawning habitats. Three components of the larval pheromone have been identified and tested in laboratory settings: petromyzonol sulfate, petromyzosterol disulfate, and petromyzonamine disulfate. Here, we report the first field test of six mixtures of synthetic versions of these pheromone components, and we compare lamprey responses to these with those elicited by the complete larval odor in a natural stream. Exposure to larval odor both increased upstream movement and attracted migrants into the portion of a channel containing the odor. No tested combination of synthetic pheromone components proved similarly attractive. These findings suggest the existence of unknown additional components of the pheromone that await discovery and are likely necessary if the pheromone is to be useful in management of this pest. Further, we hypothesize that the complete pheromone mixture is necessary to attract migrants into spawning habitat at the conclusion of the migration, whereas a partial pheromone may be effective at the transition from lake to stream when natural factors both dilute and alter the ratio of components from that actually emitted by sea lamprey larvae.
Collapse
Affiliation(s)
- Trevor D Meckley
- Department of Fisheries and Wildlife, Michigan State University, 480 Wilson Rd., Room 13, East Lansing, MI 48824, USA
| | | | | |
Collapse
|
3
|
Adnani N, Michel CR, Bugni TS. Universal quantification of structurally diverse natural products using an evaporative light scattering detector. JOURNAL OF NATURAL PRODUCTS 2012; 75:802-6. [PMID: 22471612 PMCID: PMC3338159 DOI: 10.1021/np300034c] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/12/2012] [Indexed: 05/31/2023]
Abstract
A lack of good methods for absolute quantification of natural products has limited the accuracy of high-throughput screening. Many currently used methods for quantification are either too slow or not amenable to the structural diversity of natural products. Recent developments in low-temperature evaporative light scattering detectors (ELSD-LT) have overcome several historical limitations of ELSDs, including analyte decomposition and low sensitivity. Primarily, ELSDs have been used for relative quantification and detection of compounds that lack a UV chromophore. In this study, we employ an ELSD-LT for absolute quantification of natural products. Calibration curves were constructed using a weighted least-squares analysis for a diverse set of natural products and other compounds. An average calibration curve was evaluated for the "universal" quantification of natural products. Optimization of ELSD-LT hardware and parameters improved sensitivity and throughput and established the utility of ELSD-LT for quantification of large natural product libraries.
Collapse
Affiliation(s)
- Navid Adnani
- Pharmaceutical
Sciences Division, University of Wisconsin−Madison, 777 Highland Avenue, Madison, Wisconsin 53705, United States
| | - Cole R. Michel
- Pharmaceutical
Sciences Division, University of Wisconsin−Madison, 777 Highland Avenue, Madison, Wisconsin 53705, United States
| | - Tim S. Bugni
- Pharmaceutical
Sciences Division, University of Wisconsin−Madison, 777 Highland Avenue, Madison, Wisconsin 53705, United States
| |
Collapse
|
4
|
Clarot I, Storme-Paris I, Chaminade P, Estevenon O, Nicolas A, Rieutord A. Simultaneous quantitation of tobramycin and colistin sulphate by HPLC with evaporative light scattering detection. J Pharm Biomed Anal 2009; 50:64-7. [DOI: 10.1016/j.jpba.2009.03.013] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2008] [Revised: 03/12/2009] [Accepted: 03/14/2009] [Indexed: 11/26/2022]
|
5
|
Lemoff A, Yan B. Dual Detection Approach to a More Accurate Measure of Relative Purity in High-Throughput Characterization of Compound Collections. ACTA ACUST UNITED AC 2008; 10:746-51. [PMID: 18698828 DOI: 10.1021/cc800100g] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Andrew Lemoff
- St. Jude Children’s Research Hospital, Memphis, Tennessee 38105, and Shandong University, Jinan, China 250100
| | - Bing Yan
- St. Jude Children’s Research Hospital, Memphis, Tennessee 38105, and Shandong University, Jinan, China 250100
| |
Collapse
|
6
|
Liang X, Patel H, Young J, Shah P, Raglione T. The practical application of implementing the equimolar response principle of chemiluminescent nitrogen detection in pharmaceutical analysis. J Pharm Biomed Anal 2008; 47:723-30. [DOI: 10.1016/j.jpba.2008.02.026] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2007] [Revised: 02/19/2008] [Accepted: 02/21/2008] [Indexed: 10/22/2022]
|
7
|
Qi M, Zhou H, Ma X, Zhang B, Jefferies C, Yan B. Feasibility of a self-calibrated LC/MS/UV method to determine the absolute amount of compounds in their storage and screening lifecycle. JOURNAL OF COMBINATORIAL CHEMISTRY 2008; 10:162-5. [PMID: 18281955 DOI: 10.1021/cc800007k] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Minghua Qi
- School of Pharmaceutical Sciences, Shandong University, Jinan, China
| | | | | | | | | | | |
Collapse
|
8
|
Ackermann BL, Berna MJ, Eckstein JA, Ott LW, Chaudhary AK. Current applications of liquid chromatography/mass spectrometry in pharmaceutical discovery after a decade of innovation. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2008; 1:357-396. [PMID: 20636083 DOI: 10.1146/annurev.anchem.1.031207.112855] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Current drug discovery involves a highly iterative process pertaining to three core disciplines: biology, chemistry, and drug disposition. For most pharmaceutical companies the path to a drug candidate comprises similar stages: target identification, biological screening, lead generation, lead optimization, and candidate selection. Over the past decade, the overall efficiency of drug discovery has been greatly improved by a single instrumental technique, liquid chromatography/mass spectrometry (LC/MS). Transformed by the commercial introduction of the atmospheric pressure ionization interface in the mid-1990s, LC/MS has expanded into almost every area of drug discovery. In many cases, drug discovery workflow has been changed owing to vastly improved efficiency. This review examines recent trends for these three core disciplines and presents seminal examples where LC/MS has altered the current approach to drug discovery.
Collapse
Affiliation(s)
- Bradley L Ackermann
- Eli Lilly and Company, Greenfield Laboratories, Greenfield, Indiana 46140, USA.
| | | | | | | | | |
Collapse
|
9
|
|
10
|
de Villiers A, Górecki T, Lynen F, Szucs R, Sandra P. Improving the universal response of evaporative light scattering detection by mobile phase compensation. J Chromatogr A 2007; 1161:183-91. [PMID: 17568599 DOI: 10.1016/j.chroma.2007.05.078] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2007] [Revised: 05/22/2007] [Accepted: 05/25/2007] [Indexed: 11/23/2022]
Abstract
Mobile phase compensation, first reported for the charged aerosol detector (CAD), was used as a suitable method to overcome problems related to the mobile phase-dependent response of the evaporative light scattering detector (ELSD). Mobile phase compensation was effectively performed both in the flow injection- and in gradient modes. Without compensation, the response factors of the ELSD for six sulfonamide drugs differed by a factor of two when varying the mobile phase composition between 10 and 90% acetonitrile. This change could be effectively eliminated using the technique of mobile phase compensation, where a secondary pump with a reversed gradient was used to provide the detector with a constant composition of the mobile phase. For identical experimental conditions, the ELSD showed a nearly constant, albeit somewhat reduced, response with compensation. This indicates that under such conditions, the ELSD behaved as a concentration-sensitive detector. The analysis of sulfonamides drugs at 0.05% level using gradient UPLC-ELSD separation with mobile phase compensation is demonstrated.
Collapse
Affiliation(s)
- André de Villiers
- Pfizer Analytical Research Centre, Ghent University, Krijgslaan 281 S4-bis, B-9000 Ghent, Belgium
| | | | | | | | | |
Collapse
|
11
|
Emmenegger C, Reinhardt A, Hueglin C, Zenobi R, Kalberer M. Evaporative light scattering: a novel detection method for the quantitative analysis of humic-like substances in aerosols. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2007; 41:2473-8. [PMID: 17438802 DOI: 10.1021/es061095t] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
The chemical composition of organic atmospheric aerosols is only poorly understood. Although a significant fraction of organic aerosols consists of humic-like substances (HULIS), only little is known about this class of compound, and accurate quantification remains difficult, partly due to the lack of appropriate standards. Here, evaporative light-scattering detection (ELSD) was applied for the first time to quantify water-soluble HULIS in aerosol particles smaller than 1 microm. This detection method was shown to be suitable for the quantification of compounds with unknown structures and lacking appropriate quantification standards. As compared to organic carbon determination of isolated HULIS, no organic carbon/organic mass (OC/OM) conversion factor needs to be applied with ELSD and therefore eliminates this significant uncertainty factor of the OC/OM method, which is frequently used to quantify HULIS. Solid-phase extraction and size-exclusion chromatography were applied to separate inorganic ions and low molecular weight compounds from HULIS before ELSD quantification. The ELSD itself provides an additional separation step where low volatility HULIS are separated from high volatility, small compounds. Electrospray ionization mass spectrometry was used to identify the molecular weight range of the compounds quantified with ELSD. The most intensive peaks were in the range of m/z 200-500, with some masses upto m/z800. We showed that UV detection using fulvic acid as surrogate quantification standard underestimates the HULIS concentration by a factor of 1.1 to 2.5, which is in agreement with earlier studies. During a 6 week winter 2005-2006 campaign at a suburban site near Zurich, Switzerland, an average of 1.1 microg/m(3) HULIS was found, which is about4-6% of the total particle mass smaller than 1 microm (PM1) and 10-35% of the organic matter in PM1.
Collapse
Affiliation(s)
- Christian Emmenegger
- Department of Chemistry and Applied Biosciences, Wolfgang-Paulistrasse 10, ETH Zürich, CH-8093 Zürich, Switzerland
| | | | | | | | | |
Collapse
|
12
|
Yan B, Zhao J, Leopold K, Zhang B, Jiang G. Structure-dependent response of a chemiluminescence nitrogen detector for organic compounds with adjacent nitrogen atoms connected by a single bond. Anal Chem 2007; 79:718-26. [PMID: 17222042 DOI: 10.1021/ac061682x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
High-throughput screening (HTS) of chemical libraries is indispensable for drug discovery research. However, the HTS data quality for lead discovery, lead optimization, and quantitative structure activity relationship studies has been severely compromised due to the uncertain compound concentrations in screening plates. In order to address this issue, we compared various high-throughput technologies for quantification of compounds in microtiter plate format without the need for authentic compounds as standards and identified the chemiluminescence nitrogen detector (CLND) as the method of choice at the present time. However, the structure dependence of this detector has not been well studied. A proposed rule suggested that the only exception to equimolar response is for compounds that contain adjacent nitrogen atoms. The response should be zero when the adjacent nitrogen atoms are connected by a double bond and 0.5 when they are connected by a single bond. In this investigation, we studied a broad range of compounds with isolated and adjacent nitrogen atoms. We confirmed that compounds with isolated nitrogen atoms produce an equimolar response with a 15-20% variation depending on structures and compounds with adjacent nitrogen atoms connected by a double bond giving nearly zero response. We discovered that the CLND response for compounds containing adjacent nitrogen atoms that are connected with a single bond is highly structure dependent. Substitutions on the nitrogen atoms or nearby in the molecule can increase the CLND response to approach a value higher than the predicted value 0.5 (maximal value 0.82/nitrogen atom). Without substitution, much lower values than predicted (minimal value 0.0-0.08/nitrogen atom) are obtained. Therefore, the prediction of response of 0.5/nitrogen atom for compounds with adjacent nitrogen atoms connected by a single bond should be abandoned. Compounds with similar structures should be used to generate calibration curves for quantification of this class of compounds.
Collapse
Affiliation(s)
- Bing Yan
- School of Pharmaceutical Sciences, Shandong University, Jinan, Shandong, China; Bristol-Myers Squibb Pharmaceutical Research Institute, Wallingford, Connecticut 06492, USA.
| | | | | | | | | |
Collapse
|
13
|
Guisbert AL, Sharp VS, Peterson JA, Risley DS. ENANTIOMERIC SEPARATION OF AN AMPA ANTAGONIST USING A CHIROBIOTIC T™ COLUMN WITH HPLC AND EVAPORATIVE LIGHT-SCATTERING DETECTION. J LIQ CHROMATOGR R T 2007. [DOI: 10.1081/jlc-100101504] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Andrea L. Guisbert
- a Lilly Research Laboratories, Pharmaceutical Sciences Division, Lilly Corporate Center , Eli Lilly and Company , Indianapolis, IN, 46285, U.S.A
| | - V. Scott Sharp
- a Lilly Research Laboratories, Pharmaceutical Sciences Division, Lilly Corporate Center , Eli Lilly and Company , Indianapolis, IN, 46285, U.S.A
| | - Jeffrey A. Peterson
- a Lilly Research Laboratories, Pharmaceutical Sciences Division, Lilly Corporate Center , Eli Lilly and Company , Indianapolis, IN, 46285, U.S.A
| | - Donald S. Risley
- b Lilly Research Laboratories, Pharmaceutical Sciences Division, Lilly Corporate Center , Eli Lilly and Company , Indianapolis, IN, 46285, U.S.A
| |
Collapse
|
14
|
Baertschi SW. Analytical methodologies for discovering and profiling degradation-related impurities. Trends Analyt Chem 2006. [DOI: 10.1016/j.trac.2006.05.012] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
15
|
McClintic C, Remick DM, Peterson JA, Risley DS. Novel Method for the Determination of Piperazine in Pharmaceutical Drug Substances Using Hydrophilic Interaction Chromatography and Evaporative Light Scattering Detection. J LIQ CHROMATOGR R T 2006. [DOI: 10.1081/jlc-120025426] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Carlie McClintic
- a Department of Chemistry , University of Indianapolis , Indianapolis, Indiana, USA
| | - David M. Remick
- b Eli Lilly and Company, Biopharmaceutics and Drug Delivery, Lilly Research Laboratories , Lilly Corporate Center , Indianapolis, Indiana, USA
| | - Jeffrey A. Peterson
- b Eli Lilly and Company, Biopharmaceutics and Drug Delivery, Lilly Research Laboratories , Lilly Corporate Center , Indianapolis, Indiana, USA
| | - Donald S. Risley
- b Eli Lilly and Company, Biopharmaceutics and Drug Delivery, Lilly Research Laboratories , Lilly Corporate Center , Indianapolis, Indiana, USA
| |
Collapse
|
16
|
Risley DS, Yang WQ, Peterson JA. Analysis of mannitol in pharmaceutical formulations using hydrophilic interaction liquid chromatography with evaporative light-scattering detection. J Sep Sci 2006; 29:256-64. [PMID: 16524100 DOI: 10.1002/jssc.200500253] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
This study demonstrates the use of hydrophilic interaction liquid chromatography (HILIC) for the separation of both active and inactive ingredients in pharmaceuticals from a single injection. Excipients commonly used in parenteral formulations were separated using a gradient method employing increasing aqueous composition. An evaporative light-scattering detector (ELSD) provided direct detection of inactive excipients and inorganic salts lacking UV chromophores. Analyses of Gemzar parenteral formulations using optimized isocratic HILIC-ELSD method conditions were performed based on retention time screening from the gradient assay. All of the components were efficiently separated using a TSK-Gel Amide 80 column including gemcitabine, mannitol, and sodium cation demonstrating the qualitative capability of the technique. The method was thoroughly validated for mannitol content to access the quantitative potential of the technique. Validation parameters included linearity, accuracy, specificity, solution stability, repeatability, and intermediate precision. Overall, the method described in this report proved to be very robust and represents a novel technique to conveniently separate and detect the active and inactive components in pharmaceuticals both quickly and accurately.
Collapse
Affiliation(s)
- Donald S Risley
- Eli Lilly and Company, Pharmaceutical Sciences Research and Development, Lilly Research Laboratories, Indianapolis IN 46285, USA.
| | | | | |
Collapse
|
17
|
Yuan D, Petersen C, Rynd M, Mainquist J, Meyer A, Isbell JJ. A novel method for immediate post-purification purity determination of fractions collected during high-throughput purification. J Chromatogr A 2005; 1092:228-34. [PMID: 16199230 DOI: 10.1016/j.chroma.2005.07.080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2005] [Revised: 07/06/2005] [Accepted: 07/11/2005] [Indexed: 10/25/2022]
Abstract
Following purification, the fractions of purified samples typically are analyzed to determine the relative purities of each fraction. We report a novel technique for performing post-purification analysis immediately after each preparative LC/MS run. The Single Pass Compound Purification and Analysis System (SPACPASS) samples and stores a representative aliquot from the fraction while it is being collected. Demonstrated for '1:1' fraction collections, this method of fraction purity assessment streamlined sample processing by reducing post-purification sample handling. For 97% of the collected fractions, this technique provided relative purities to within +/-5% when compared with more traditional post-purification analysis.
Collapse
Affiliation(s)
- Ding Yuan
- Department of Analytical and Bioanalytical Chemistry, Genomics Institute of the Novartis Research Foundation, 10675 John Jay Hopkins Drive, San Diego, CA 92121, USA
| | | | | | | | | | | |
Collapse
|
18
|
Clarot I, Regazzeti A, Auzeil N, Laadani F, Citton M, Netter P, Nicolas A. Analysis of neomycin sulfate and framycetin sulfate by high-performance liquid chromatography using evaporative light scattering detection. J Chromatogr A 2005; 1087:236-44. [PMID: 16130719 DOI: 10.1016/j.chroma.2005.05.054] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A rapid and simple method for the determination of main components and related substances of both neomycin sulfate and framycetin sulfate by HPLC and evaporative light scattering detection (ELSD) is described. The method was also used to determine the neomycin B and the sample sulfate content. Detection and quantitation of aminoglycoside antibiotics are problematic because of the lack of UV absorbing chromophore. The use of a universal detector avoids the need for sample derivatization or use of specific detector based on pulsed amperometry described to be difficult in routine assays. Separation was performed with a Polaris C18 150 mm x 4.6 mm i.d., 3 microm reversed-phase column with a solution of 170mM trifluoroacetic acid (TFA) mobile phase at a flow rate of 0.2 mL/min. The chromatographic parameters were optimized with the help of experimental design software. Mass spectrometry (MS) was employed to confirm the ELSD profile. The final method was validated using methodology described by the International Conference of Harmonization in the field of Active Pharmaceutical Ingredients. Commercial samples of different sources were analyzed and results were in good agreement with specifications of the European Pharmacopoeia.
Collapse
Affiliation(s)
- I Clarot
- Laboratoire de Chimie Analytique, UMR 7561 CNRS-UHP, Faculté de Pharmacie, 5 rue Albert Lebrun, F-54000 Nancy Cedex, France.
| | | | | | | | | | | | | |
Collapse
|
19
|
Lane S, Boughtflower B, Mutton I, Paterson C, Farrant D, Taylor N, Blaxill Z, Carmody C, Borman P. Toward Single-Calibrant Quantification in HPLC. A Comparison of Three Detection Strategies: Evaporative Light Scattering, Chemiluminescent Nitrogen, and Proton NMR. Anal Chem 2005; 77:4354-65. [PMID: 16013846 DOI: 10.1021/ac050257l] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
There is an urgent need for detection technologies that enable accurate and precise quantification of solutions containing small organic molecules in a manner that is rapid, cheap, non-labor-intensive, readily automated, and without a requirement for specific analyte standards. We provide a theoretical analysis that predicts that the logarithmic nature of the working domain of the evaporative light-scattering detector (ELSD) will normally bias toward underestimation of chromatographically resolved impurities, resulting in an overestimation of analyte purity. This analysis is confirmed by experiments with flow injection analysis (FIA) and gradient reversed-phase high performance liquid chromatography (RP-HPLC). Quantification is further compromised by the dependence of response parameters on the matrix composition and hence on the retention time of the analyte. Attempts were made to ameliorate these problems by using the response surface of a single compound to calibrate throughout the HPLC gradient. A chemiluminescent nitrogen detector (CLND) was also used in a similar manner, and the performance of the two techniques were compared against those of each other and that of a reference standard technique. A protocol for this purpose was developed using proton nuclear magnetic resonance (1H NMR) and the ERETIC method to enable quantification by integrating proton signals. The double-blind comparison exercise confirmed molar nitrogen CLND response to be sufficiently stable and robust across a methanol gradient to be used with a single external nitrogenous calibrant to quantify nitrogen-containing compounds of known molecular formula. The performance of HPLC-CLND was very similar to that of NMR, while that of HPLC-ELSD was seen to be significantly worse, showing it to be unsuitable for the purpose of single-calibrant quantification. We report details and experience of our use of RP-HPLC-CLND-MS to characterize and quantify small amounts of solutions of novel compounds at nominal levels of 10mM in microtiter plate (MTP) format.
Collapse
Affiliation(s)
- Steve Lane
- Analytical Sciences, CASS, Analytical Sciences, Chemical Development, GlaxoSmithKline, Gunnels Wood Road, Stevenage SG1 2NY, UK
| | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Fries HE, Evans CA, Ward KW. Evaluation of evaporative light-scattering detection for metabolite quantification without authentic analytical standards or radiolabel. J Chromatogr B Analyt Technol Biomed Life Sci 2005; 819:339-44. [PMID: 15833299 DOI: 10.1016/j.jchromb.2005.02.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2005] [Revised: 01/27/2005] [Accepted: 02/10/2005] [Indexed: 11/25/2022]
Abstract
Development of a sensitive and specific technique for the quantitation of drug metabolites without the use of synthetic analytical standards or radiolabel would represent a major advance in preliminary route of metabolism screening in drug discovery. In this study, the ability of evaporative light-scattering detection (ELSD) to quantify metabolites of 7-ethoxycoumarin (EC) was evaluated. Because ELSD operates as a mass detector, the complex nature of in vitro-derived samples from hepatocyte incubations resulted in an inability to detect the analytes of interest in this matrix using ELSD. Additionally, the gradient nature of the analysis required to temporally separate ethoxycoumarin from its metabolites and matrix components interfered with the ELSD response. Furthermore, using less-complex contrived mixtures, ELSD demonstrated insufficient sensitivity (limit of detection of 1000-10,000 ng/mL) and an inconsistent inter-analyte response. Together, the limitations outlined in these experiments demonstrate that ELSD is at present an inadequate technique for generating semi-quantitative data on metabolites in drug discovery.
Collapse
Affiliation(s)
- Harvey E Fries
- Preclinical Drug Discovery, Cardiovascular and Urogenital Center of Excellence in Drug Discovery, GlaxoSmithKline, King of Prussia, PA 19406, USA.
| | | | | |
Collapse
|
21
|
Pack BW, Risley DS. Evaluation of a monolithic silica column operated in the hydrophilic interaction chromatography mode with evaporative light scattering detection for the separation and detection of counter-ions. J Chromatogr A 2005; 1073:269-75. [PMID: 15909529 DOI: 10.1016/j.chroma.2004.09.061] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
In this work a monolithic silica column operated in the hydrophilic interaction chromatography (HILIC) mode in conjunction with an evaporative light scattering detector (ELSD) was investigated. Lithium, sodium and potassium were used as the test counter-ions for this evaluation. Chromatographic properties of this column operated in the HILIC mode were determined by varying key mobile phase parameters, such as pH, flow rate, buffer strength, acid and organic modifier. As organic content was increased from 60 to 90% acetonitrile, retention time increased on average by a factor of seven for the test cations listed above. Buffer concentration and pH were also observed to have an effect, although not as significant as the HILIC effect that was observed by changing organic content. Flow rates up to 5 mL/min were utilized to perform counter-ion separations in less than 3 min. After examining the changes in retention, resolution, and peak shape an optimized method was established and then further evaluated for linearity, reproducibility, and limit of detection (LOD) for sodium. Linearity was acceptable with an R2 value of 0.999 across the working-standard range and a LOD of 0.1 microg/mL was calculated. The reproducibility on the counter-ion determination from pharmaceutical sodium salts was 1.6% R.S.D. on average, and the accuracy of the counter-ion prediction was approximately 3% from theory when salt content was corrected for potency.
Collapse
Affiliation(s)
- Brian W Pack
- Eli Lilly and Company, Pharmaceutical Product Research and Development, Lilly Research Laboratories, Indianapolis, IN 46285, USA.
| | | |
Collapse
|
22
|
Clarot I, Chaimbault P, Hasdenteufel F, Netter P, Nicolas A. Determination of gentamicin sulfate and related compounds by high-performance liquid chromatography with evaporative light scattering detection. J Chromatogr A 2004; 1031:281-7. [PMID: 15058594 DOI: 10.1016/j.chroma.2003.12.032] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
A rapid and simple method for the separation and quantitation of gentamicin sulfate by HPLC coupled with evaporative light scattering detection (ELSD) has been developed. Detection of the different components of gentamicin is problematic because of the lack of UV absorbing chromophore. The use of the universal ELSD avoids the need for sample derivatization or use of specific detector such as pulsed amperometry. Separation was performed on a highpurity C18 125 mm x 4 mm i.d., 3 microm, reversed phase column with 48.5 mM trifluoroacetic acid-methanol (97:3, v/v), as mobile phase at a flow rate of 0.7 ml/min. The influence of the gas nature, gas pressure and temperature of the drift tube of the detector on the detection response was investigated. Optimization was performed with the help of a specific experimental design software. This method allows the determination of the composition in components C1, C1a, C2, C2a and C2b of gentamicin sulfate samples. Mass spectrometry was employed to confirm the ELSD chromatographic profile. The method was validated using methodology described by the International Conference of Harmonization in the field of Medicinal Substances. Commercial samples of different sources were analyzed and results were in good agreement with specifications of both European and United States Pharmacopoeia.
Collapse
Affiliation(s)
- I Clarot
- Laboratoire de Chimie Analytique, UMR 7561 CNRS-UHP, Faculté de Pharmacie, Université Henri-Poincaré-Nancy I, 5 Rue Albert Lebrun, F-54000 Nancy, France.
| | | | | | | | | |
Collapse
|
23
|
Yan B, Fang L, Irving M, Zhang S, Boldi AM, Woolard F, Johnson CR, Kshirsagar T, Figliozzi GM, Krueger CA, Collins N. Quality control in combinatorial chemistry: determination of the quantity, purity, and quantitative purity of compounds in combinatorial libraries. JOURNAL OF COMBINATORIAL CHEMISTRY 2003; 5:547-59. [PMID: 12959555 DOI: 10.1021/cc030008f] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The quality of combinatorial libraries determines the success of biological screening in drug discovery programs. In this paper, we evaluate and compare various methods for measuring identity, purity, and quantity (yield) of combinatorial libraries. Determination of quantitative purity reveals the true library quality and often indicates potential quality problems before full-scale library production. The relative purity can be determined for every member in a large library in a high-throughput mode, but must be cautiously interpreted. In particular, many impurities are not observable by relative purity measurements using detectors such as UV(214), UV(254), and evaporative light-scattering detection. These "invisible" impurities may constitute a significant portion of the sample weight. We found that TFA, plastic extracts, inorganic compounds, and resin washout are among these impurities. With compelling evidence, we reach a conclusion that purification is the only way to remove "invisible" impurities and improve the quantitative purity of any compound even though some compounds may have a high relative purity before purification.
Collapse
Affiliation(s)
- Bing Yan
- ChemRx Division, Discovery Partners International, Inc., 385 Oyster Point Boulevard, South San Francisco, California 94080, USA.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
24
|
Cheng X, Hochlowski J. Current application of mass spectrometry to combinatorial chemistry. Anal Chem 2002; 74:2679-90. [PMID: 12090657 DOI: 10.1021/ac020186f] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Xueheng Cheng
- Global Pharmaceutical Research and Development, Abbott Laboratories, Abbott Park, Illinois 60064, USA
| | | |
Collapse
|
25
|
Nussbaum MA, Baertschi SW, Jansen PJ. Determination of relative UV response factors for HPLC by use of a chemiluminescent nitrogen-specific detector. J Pharm Biomed Anal 2002; 27:983-93. [PMID: 11836061 DOI: 10.1016/s0731-7085(01)00545-3] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Ultraviolet (UV) absorbance is the most widely used detection method for high-performance liquid chromatography (HPLC) separations. In pharmaceutical analysis, purity determinations often include quantitation of related impurities based on relative HPLC peak areas obtained at a specific wavelength. In order for this quantitation to accurately reflect weight percentages of impurities, the relative UV response factors (absorptivities) at the given wavelength must be known. In this work, we present a convenient method for determining relative UV response factors on-line, without isolation or purification of impurities, without standards, and without requiring known analyte concentrations. The procedure described makes use of a chemiluminescent nitrogen-specific HPLC detector (CLND) in conjunction with a UV detector. The CLND response is directly proportional to the number of moles of nitrogen in each eluting peak, and can, therefore, be used to determine relative amounts of each nitrogen-containing impurity present in the sample, provided the molecular formulas are known (e.g. from exact mass LC-MS). It is a simple matter, then, to determine the relative UV response factors from the UV area ratios obtained for the same sample. The feasibility and accuracy of this method is demonstrated for gradient HPLC separations of commercially available compounds of widely varying structures. Finally, the method's utility in obtaining accurate mass balance is demonstrated by application to photodegradation of nifedipine.
Collapse
Affiliation(s)
- M A Nussbaum
- Chemistry Department, Hillsdale College, 33 E. College St., Hillsdale, MI 49242, USA.
| | | | | |
Collapse
|
26
|
Kofod-Hansen M, Peschke B, Thøgersen H. Head-to-backbone cyclization of peptides on solid support by nucleophilic aromatic substitution. J Org Chem 2002; 67:1227-32. [PMID: 11846667 DOI: 10.1021/jo016269y] [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: 11/29/2022]
Abstract
A new versatile synthetic route is presented for the cyclization of tripeptides on solid support using nucleophilic aromatic substitution in the cyclization step. Identification of all conformers within a limit of 3 kcal/mol from the identified global minimum conformations by Monte Carlo conformational searching reveals that five out of six synthesized compounds have well-defined peptide backbone conformational properties. This was determined by clustering the identified conformers against a filter of seven to nine torsion angles in the peptide backbone. Thus, the results meet our goal to find synthetic routes to peptides that are conformationally sufficiently locked to serve as convenient leads for further development of pharmacophoric models. The strategy is based on Fmoc-peptide chemistry on a N-aminoethyl-substituted glycine bound to the commercially available Rink amide PS-resin. After deprotection of the N-terminus of the tripeptide, it is acylated with a fluoronitrobenzoic acid. Subsequently, a Boc group on the N-bound aminoethyl substituent is selectively deprotected allowing cyclization from the head (N-terminus) to the backbone substituent, thereby leading to the desired cyclized tripeptides. A number of representative examples of peptides cyclized by this method have been synthesized and characterized by NMR. Protecting groups that allow the incorporation of side chain functionalized amino acids have been found. Thus, the route provides access to generic libraries of conformationally restricted peptide sequences expressing a range of proteinogenic pharmacophores.
Collapse
Affiliation(s)
- Mikael Kofod-Hansen
- Discovery Chemistry, Novo Nordisk A/S, Novo Nordisk Park, DK-2760 Måløv, Denmark.
| | | | | |
Collapse
|
27
|
Triolo A, Altamura M, Cardinali F, Sisto A, Maggi CA. Mass spectrometry and combinatorial chemistry: a short outline. JOURNAL OF MASS SPECTROMETRY : JMS 2001; 36:1249-1259. [PMID: 11754116 DOI: 10.1002/jms.238] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The rapid evolution of combinatorial chemistry in recent years has led to a dramatic improvement in synthetic capabilities. The goal is to accelerate the discovery of molecules showing affinity against a target, such as an enzyme or a receptor, through the simultaneous synthesis of a great number of structurally diverse compounds. This is done by generating combinatorial libraries containing as many as hundreds or thousands of compounds. The need to test all these compounds led to the development of high-throughput screening (HTS) techniques, and also high-throughput analytical techniques capable of assessing the occurrence, structure and purity of the products. In order to be applied effectively to the characterization of combinatorial libraries, an analytical technique must be adequately sensitive (to analyse samples which are typically produced in nanomole amounts or less), fast, affordable and easy to automate (to minimize analysis time and operator intervention). Although no method alone can meet all the analytical challenges underlying this task, the recent progress in mass spectrometric (MS) instrumentation renders this technique an essential tool for scientists working in this area. We describe here relevant aspects of the use of MS in combinatorial technologies, such as current methods of characterization, purification and screening of libraries. Some examples from our laboratory deal with the analysis of pooled oligomeric libraries containing n x 324(n = 1, 2) compounds, using both on-line high-performance liquid chromatography/MS with an ion trap mass spectrometer, and direct infusion into a triple quadrupole instrument. In the first approach, MS and product ion MS/MS with automatic selection of the precursor were performed in one run, allowing library confirmation and structural elucidation of unexpected by-products. The second approach used MS scans to characterize the entire library and also precursor ion and neutral loss scans to detect selectively components with given structural characteristics.
Collapse
Affiliation(s)
- A Triolo
- Menarini Ricerche SpA, via Sette Santi 3, 50131 Florence, Italy.
| | | | | | | | | |
Collapse
|
28
|
Hobbs DW, Guo T. Library design concepts and implementation strategies. J Recept Signal Transduct Res 2001; 21:311-56. [PMID: 11789688 DOI: 10.1081/rrs-100107922] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- D W Hobbs
- Pharmacopeia, Inc, Princeton, New Jersey, USA
| | | |
Collapse
|
29
|
Peschke B, Gredal Bundgaard J, Breinholt J. Synthesis of amino alcohols on solid support via sulfonium-ion mediated Darzens reaction. Tetrahedron Lett 2001. [DOI: 10.1016/s0040-4039(01)00952-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
30
|
Fang L, Pan J, Yan B. High-throughput determination of identity, purity, and quantity of combinatorial library members using LC/MS/UV/ELSD. Biotechnol Bioeng 2001; 71:162-71. [PMID: 11288070 DOI: 10.1002/1097-0290(2000)71:2<162::aid-bit1006>3.0.co;2-a] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We have used a high-throughput LC/MS/UV/ELSD method to rapidly determine the absolute quantity and purity of 42 organic compounds from seven lead discovery libraries. A general calibration curve generated from a different set of 42 compounds with seven different scaffolds was used in this analysis. We have also studied 33 organic compounds with different molecular weight (MW) by LC/MS/UV/ELSD to investigate the effect of MW on ELSD response and the accuracy for purity and quantity measurement using UV(214) and ELSD. A general ELSD calibration curve from these compounds was also generated to quantify 42 library compounds. Purity measurement by ELSD underestimates the amounts of impurities due to a reduced ELSD response from smaller molecular weight impurities often produced in library synthesis. Absolute quantity determination by ELSD is more accurate (RSD 28%) than that by UV(214) (48%) using a calibration curve generated from the same set of compounds with diverse MWs. Error assessment for the measurement of absolute quantity of a class of commercial compounds and a class of representing reference compounds from seven diverse lead discovery libraries shows that structurally related compounds should be used to generate calibration curves to sustain smaller deviation.
Collapse
Affiliation(s)
- L Fang
- ChemRx Advanced Technologies, South San Francisco, California 94080, USA
| | | | | |
Collapse
|
31
|
Jiang Y, Lee CS. On-line coupling of hollow fiber membranes with electrospray ionization mass spectrometry for continuous affinity selection, concentration and identification of small-molecule libraries. JOURNAL OF MASS SPECTROMETRY : JMS 2001; 36:664-669. [PMID: 11433540 DOI: 10.1002/jms.168] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Combinatorial chemistry has been widely employed in the pharmaceutical industry in the effort towards drug discovery. Rapid and sensitive screening of lead candidates among library compounds has thus imposed significant analytical challenges in recent years. This work involved the development of a continuous affinity capture and concentration system, providing cost-effective and structural analysis of drug candidates in a flow-through format. The system combines the strengths of a hollow fiber dialysis membrane of ease and speed of purification and concentration with the specificity of affinity interactions in solution. The complexes between the lead compounds and the affinity binding proteins are separated from other chemical components inside a dialysis hollow fiber as the result of their differences in size. The affinity complexes are further concentrated inside a second dialysis fiber. The concentrated drug candidates are liberated from the binding proteins in a microdialysis junction and can be directly identified using electrospray ionization mass spectrometry. Two model systems, including human serum albumin-warfarin-related compounds and anti-phenobarbital antibody-barbiturates, were employed for mechanistic studies of dialysis versus dissociation kinetics and competitive selection of drug candidates according to their binding strengths.
Collapse
Affiliation(s)
- Y Jiang
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, USA
| | | |
Collapse
|
32
|
Sims JL. Proposed performance qualification and calibration method for evaporative light scattering detectors. Chromatographia 2001. [DOI: 10.1007/bf02491074] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
33
|
Kassel DB. Combinatonial chemistry and mass spectrometry in the 21st century drug discovery laboratory. Chem Rev 2001; 101:255-67. [PMID: 11712247 DOI: 10.1021/cr990085q] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- D B Kassel
- DuPont Pharmaceuticals Research Laboratories, 4570 Executive Drive, Suite 400, San Diego, California 92121, USA.
| |
Collapse
|
34
|
Coates WJ, Hunter DJ, MacLachlan WS. Successful implementation of automation in medicinal chemistry. Drug Discov Today 2000; 5:521-527. [PMID: 11084388 DOI: 10.1016/s1359-6446(00)01571-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Automation in medicinal chemistry is often seen simply as a part of the combinatorial chemistry technologies used to meet the need for large, diverse screening collections for lead generation. However, the application of automation to the lead optimization phase of drug discovery offers the prospect of reduced cycle times via increased efficiency in target compound preparation. The realization of this goal requires the integration of efficient processes with equipment capable of delivering quality compounds - and, of course, the skilled medicinal chemists.
Collapse
Affiliation(s)
- WJ Coates
- Combinatorial and Chemical Technologies, SmithKline Beecham Pharmaceuticals, New Frontiers Science Park (North), Third Avenue, Harlow, CM19 5AW., Essex, UK
| | | | | |
Collapse
|
35
|
Blackwell JA, Tang L, Xiang D. High throughput screening or drug impurity profiles using gradients in normal phase chromatography. Chromatographia 2000. [DOI: 10.1007/bf02490558] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
36
|
Süssmuth RD, Jung G. Impact of mass spectrometry on combinatorial chemistry. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 1999; 725:49-65. [PMID: 10226877 DOI: 10.1016/s0378-4347(98)00513-1] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In the past few years, the emergence of combinatorial chemistry has drawn increasing attention and a great deal of analytical research has been centered around this new methodology. These new methods capable of producing vast numbers of samples, which are in many cases highly complex, demand fast and reliable analytical techniques able to provide high quality information concerning sample compositions. Mass spectrometry (MS) is the method of choice to face these analytical challenges. In particular, the introduction of electrospray ionization (ESI and matrix assisted laser desorption/ionization (MALDI) have been the driving forces for many of the recent innovations, not only within the fields of the biosciences, but also in combinatorial chemistry. These ionization techniques are extremely versatile for the characterization of both single compound collections and compound mixture collections. The high-throughput capabilities, as well as many possible couplings with separation techniques (HPLC, CE) have been thus facilitated. However, mass spectrometry is not only limited to use as an instrument for synthesis control, but also plays an increasing role in the identification of active compounds from complex libraries. Recently, new initiatives for library analysis and screening have arisen from the application of the latest developments in mass spectrometry, Fourier transform ion cyclotron resonance (FTICR).
Collapse
Affiliation(s)
- R D Süssmuth
- University of Tübingen, Institute of Organic Chemistry, Germany.
| | | |
Collapse
|
37
|
Hsu BH, Orton E, Tang SY, Carlton RA. Application of evaporative light scattering detection to the characterization of combinatorial and parallel synthesis libraries for pharmaceutical drug discovery. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 1999; 725:103-12. [PMID: 10226881 DOI: 10.1016/s0378-4347(98)00529-5] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The advent of combinatorial and parallel synthesis methodologies in drug discovery have necessitated the development of analytical techniques which permit high throughput quantitative analysis of mixtures of small organic molecules. High pressure liquid chromatography with evaporative light scattering detection has become the major tool for this task. In this article we briefly review the theory of evaporative light scattering detection and the design of commercial instruments, as well as discuss the operational constraints imposed by the exigency of analyzing en masse the product libraries generated by these new drug discovery methods. The application of evaporative light scattering detection to library analysis is illustrated using examples from our library synthesis program. Complemented by ultraviolet absorbance detection for purity assessment and mass spectrometry for product identification, evaporative light scattering detection is the only technique affording sufficient accuracy and sensitivity for high throughput library analysis.
Collapse
Affiliation(s)
- B H Hsu
- Spectroscopy Section, Pharmaceutical Discovery Research, Rhône-Poulenc Rorer Pharmaceuticals, Collegeville, PA 19426, USA
| | | | | | | |
Collapse
|
38
|
Hamper BC, Snyderman DM, Owen TJ, Scates AM, Owsley DC, Kesselring AS, Chott RC. High-Throughput 1H NMR and HPLC Characterization of a 96-Member Substituted Methylene Malonamic Acid Library. ACTA ACUST UNITED AC 1999. [DOI: 10.1021/cc9800172] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Bruce C. Hamper
- AG Sector, Monsanto Company, 800 North Lindbergh Boulevard, St. Louis, Missouri 63167
| | - David M. Snyderman
- AG Sector, Monsanto Company, 800 North Lindbergh Boulevard, St. Louis, Missouri 63167
| | - Thomas J. Owen
- AG Sector, Monsanto Company, 800 North Lindbergh Boulevard, St. Louis, Missouri 63167
| | - Angela M. Scates
- AG Sector, Monsanto Company, 800 North Lindbergh Boulevard, St. Louis, Missouri 63167
| | - Dennis C. Owsley
- AG Sector, Monsanto Company, 800 North Lindbergh Boulevard, St. Louis, Missouri 63167
| | - Allen S. Kesselring
- AG Sector, Monsanto Company, 800 North Lindbergh Boulevard, St. Louis, Missouri 63167
| | - Robert C. Chott
- AG Sector, Monsanto Company, 800 North Lindbergh Boulevard, St. Louis, Missouri 63167
| |
Collapse
|
39
|
|
40
|
Taylor EW, Qian MG, Dollinger GD. Simultaneous On-Line Characterization of Small Organic Molecules Derived from Combinatorial Libraries for Identity, Quantity, and Purity by Reversed-Phase HPLC with Chemiluminescent Nitrogen, UV, and Mass Spectrometric Detection. Anal Chem 1998. [DOI: 10.1021/ac980402d] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
41
|
McCrossen SD, Bryant DK, Cook BR, Richards JJ. Comparison of LC detection methods in the investigation of non-UV detectable organic impurities in a drug substance. J Pharm Biomed Anal 1998; 17:455-71. [PMID: 9656157 DOI: 10.1016/s0731-7085(97)00235-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
HPLC Analysis with different detection methods was shown to be essential in the separation and identification of unknown organic impurities in a drug substance. The impurities were found to exhibit very weak or no response to standard ultraviolet (UV) absorption detection. LC-MS, LC-NMR, indirect, refractive index and evaporative light-scattering detection were used to quantify and identify the impurities in this specific case. The drug substance studied was found to be an ideal analyte for demonstrating the advantages and limitations of several chromatographic detection systems for impurity profile analysis.
Collapse
Affiliation(s)
- S D McCrossen
- SmithKline Beecham Pharmaceuticals, Tonbridge, Kent, UK. @inet
| | | | | | | |
Collapse
|
42
|
Kohler M, Haerdi W, Christen P, Veuthey JL. The evaporative light scattering detector: some applications in pharmaceutical analysis. Trends Analyt Chem 1997. [DOI: 10.1016/s0165-9936(97)00072-1] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
|
43
|
Fitch WL, Szardenings A, Fujinari EM. Chemiluminescent nitrogen detection for HPLC: An important new tool in organic analytical chemistry. Tetrahedron Lett 1997. [DOI: 10.1016/s0040-4039(97)00191-3] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|