Veronika R. Meyer

Pitfalls and Errors of HPLC in Pictures

• Broschiertes Buch

Produktbeschreibung

Nowadays analytical results were often obtained through High Performance Liquid Chromatography (HPLC). The complexity of the method allows on one side a wide variety of usage. On the other side it is also a source of possible errors. This book does not only list them, but illustrate them with concrete examples. The topics were presented in a clearly arranged style: a brief text with a corresponding figure. Chemists and laboratory assistants get here numerous hints how correct and reliable results could be transposed in daily laboratory work.

Produktdetails

• Verlag: Hüthig Berlin / Wiley-VCH
• 2nd ed.
• Seitenzahl: 168
• Englisch
• Abmessung: 243mm x 172mm x 10mm
• Gewicht: 390g
• ISBN-13: 9783527313723
• ISBN-10: 3527313729
• Artikelnr.: 20775486

Autorenporträt

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).

Inhaltsangabe

- Preface
- Introduction

PART I: FUNDAMENTALS
- Chromatography
- Chromatographic figures of merit
- The resolution of two peaks
- Reduced parameters
- The van Deemter curve
- Peak capacity and Number of Possible Peaks
- Statistical resolution probability: Simulation
- Statistical resolution probability: Example
- Precision and accuracy of an analytical result
- The propagation of random errors
- Reproducibility in trace analysis
- Ruggedness
- Calibration curves
- The HPLC instrument
- The detector response curve
- Noise

PART II: PITFALLS AND SOURCES OF ERROR
- Mixing of the mobile phase
- Mobile phase pH
- Adjustment of mobile phase pH
- Inadequate purity of reagents or solvents
- System peaks and quantitative analysis
- Sample preparation with solid phase extraction
- Poor choice of sample solvent and calibration curve
- Impurities in the sample
- Formation of a by-product in the sample solution
- Formation of an associate in the sample solution
- Precision and assuracy with loop injection
- Injection technique
- Injection of air
- Sample adsorption in the loop
- Extra-column volumes
- Dwell volume
- Elution at t0
- Classification to C18 reversed phases
- Different batches of stationary phase
- Chemical reaction within the column
- Double peaks from stable conformers
- Influence of temperature on the separation
- Influence of the volume flow rate on the separation
- Influence of run time and volume flow rate on gradient separations
- UV detection wavelength
- Detector overload
- Influence of the capacity factor on peak height
- Influence of the volume flow rate on peak area
- Leaks in the HPLS 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 for a 1 : 10 peak pair
- Heights for a 1 : 10 peak pair
- Quantitative analysis of a small peak
- Incompletely resolved peaks with tailing
- 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
- Ruels for accurate quantitative peak size determination
- High-low chromatography
- Control charts
- Verification of the analysis 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
- Formal quality assurance systems

- Index