Pitfalls and Errors of HPLC in Pictures

The third edition of this popular problem-solving guide for this widely-used method includes eleven completely new examples andseveral updated ones, adding up to 100 contributions about pitfalls and errors in HPLC. Each example is presented on a double page with thetext on the left-hand and a fi gure on the right-hand side, true to the motto 'a picture says more than a thousand words'. In addition, theauthor presents essential fundamentals as well as helpful strategies, such as equipment tests or quality assurance processes. New in this edition* Variability of the standard deviation* Infl uence of the acid type and concentration in the eluent* Water as an unintentional additive in the mobile phase* Inadequate purity of mobile phase water* Incomplete degassing* Inadequate stabilization of the extraction solvent* Tailing of phosphate compounds in the presence of steel* Different detection properties of diastereomers* Detector overload in ELSD* System suitability test* From repeatability to reproducibilityA must-have resource for all users - showing how to use HPLC efficiently and obtain reliable results.

List of contents

PREFACEINTRODUCTIONPART I: Fundamentals ChromatographyChromatographic Figures of MeritThe Resolution of Two PeaksReduced ParametersThe Van Deemter CurvePeak Capacity and Number of Possible PeaksStatistical Resolution Probability: SimulationStatistical Resolution Probability: ExamplePrecision and Accuracy of an Analytical ResultStandard DeviationVariability of the Standard DeviationUncertainty PropagationReproducibility in Trace AnalysisRuggednessCalibration CurvesThe HPLC InstrumentThe Detector Response CurveNoiseThe Playground Presented as an Ishikawa DiagramThe Possible and the ImpossiblePART II: Pitfalls and Sources of ErrorMixing of the Mobile PhaseMobile Phase pHAdjustment of Mobile Phase pHInfluence of the Acid Type and Concentration in the EluentWater as an Unintentional Additive in the Mobile PhaseInadequate Purity of Mobile Phase WaterInadequate Purity of a Mobile Phase SolventInadequate Purity of a Mobile Phase ReagentIncomplete DegassingSystem Peaks and Quantitative AnalysisSample Preparation with Solid Phase ExtractionInadequate Stabilization of the Extraction SolventPoor Choice of Sample Solvent: Peak DistortionPoor Choice of Sample Solvent: TailingSample Solvent and Calibration CurveImpurities in the SampleFormation of a By-Product in the Sample SolutionDecomposition by the Sample VialArtifact Peaks from the Vial SeptumFormation of an Associate in the Sample SolutionPrecision and Accuracy with Loop InjectionInjection TechniqueInjection of AirSample Adsorption in the LoopExtra-Column VolumesDwell VolumeElution at t0Classification of C18 Reversed PhasesDifferent Selectivity of C18 Reversed Phases Different Batches of Stationary PhaseChemical Reaction within the Column Tailing of Phosphate Compounds in the Presence of Steel Recovery and Peak Shape Problems with Proteins Double Peaks from Stable Conformers Influence of Temperature on the Separation Thermal Non-Equilibrium within the Column Influence of the Flow Rate on the Separation Influence of Run Time and Flow Rate on Gradient Separations UV Spectra and Quantitative Analysis UV Detection Wavelength Different Detection Properties of Diastereomers Fluorescence Quenching by Air Detector Overload in UV Detector Overload in ELSD Influence of the Retention Factor on Peak Height Influence of the Flow Rate on Peak Area Leaks in the HPLC Instrument Impairment of Precision as a Result of Noise Determination of Peak Area and Height at High Noise Peak Height Ratios Incompletely Resolved Peaks Area Rules for Incompletely Resolved Peaks Areas of a 1 : 10 Peak Pair Heights of a 1 : 10 Peak Pair Quantitative Analysis of a Small Peak Incompletely Resolved Peaks with Tailing Integration Threshold and Number of Detected Peaks Detector Time Constant and Peak Shape Quantitative Analysis in the 99% Range Correlation Coefficient of Calibration Curves PART III: Useful Strategies Column Tests Apparatus Tests Wavelength Accuracy of the UV Detector Internal Standards A Linearity Test Rules for Accurate Quantitative Peak Size Determination High-Low Chromatography Control Charts Verification of the Analytical Result by Use of a Second Method Description of Ruggedness Rules for Passing On an HPLC Method Quality Assurance in the Laboratory Standard Operating Procedures Method Validation Some Elements of Validation A Validation Example System Suitability Test From Repeatability to Reproducibility Measurement Uncertainty Formal Quality Assurance Systems INDEX

About the author

Veronika R. Meyer hat nach einer Lehre als Chemielaborantin zunächst an der Fachhochschule Burgdorf (Schweiz) Chemie studiert. Von 1976 bis 1998 hat sie an der Universität Bern mit der HPLC gearbeitet und nebenbei nach einem Universitätsabschluss auch in Chemie promoviert. Anschließend war sie am Weizmann-Institut in Rehovot (Israel) sowie an der University of Delaware, Newark, USA, tätig. 1996 hat sie sich habilitiert und seit 1998 arbeitet sie an der EMPA (Eidgenössische Materialprüfungs- und Forschungsanstalt).

Summary

The third edition of this popular problem-solving guide for this widely-used method includes eleven completely new examples and
several updated ones, adding up to 100 contributions about pitfalls and errors in HPLC. Each example is presented on a double page with the
text on the left-hand and a fi gure on the right-hand side, true to the motto 'a picture says more than a thousand words'. In addition, the
author presents essential fundamentals as well as helpful strategies, such as equipment tests or quality assurance processes.

New in this edition

* Variability of the standard deviation
* Infl uence of the acid type and concentration in the eluent
* Water as an unintentional additive in the mobile phase
* Inadequate purity of mobile phase water
* Incomplete degassing
* Inadequate stabilization of the extraction solvent
* Tailing of phosphate compounds in the presence of steel
* Different detection properties of diastereomers
* Detector overload in ELSD
* System suitability test
* From repeatability to reproducibility

A must-have resource for all users - showing how to use HPLC efficiently and obtain reliable results.

Product details

• Authors: Veronika R Meyer, Veronika R. Meyer
• Publisher: Wiley-VCH
• Languages: English
• Product format: Paperback / Softback
• Released: 01.01.2013
• EAN: 9783527332939
• ISBN: 978-3-527-33293-9
• No. of pages: 210
• Dimensions: 171 mm x 244 mm x 13 mm
• Weight: 490 g
• Illustrations: w. 70 figs.
• Subjects: Natural sciences, medicine, IT, technology > Chemistry; Chemie, chemistry, Pharmaceutical & Medicinal Chemistry, Pharmazeutische u. Medizinische Chemie, Chromatographie / Trennverfahren, Methods - Synthesis & Techniques, Organische Chemie / Methoden, Synthesen, Verfahren, Chemie / Organische Chemie, Chromatography / Separation Techniques, Flüssigkeitschromatographie, HPLC