Chromatographic integration methods / Norman Dyson.

Format:

Book

Author/Creator:

Dyson, Norman.

Series:

RSC Chromatography Monographs

RSC chromatography monographs

ISSN

Language:

English

Subjects (All):

Chromatographic analysis.

Chromatographic analysis--Data processing.

Physical Description:

1 online resource (221 p.)

Edition:

2nd ed.

Place of Publication:

Cambridge : Royal Society of Chemistry, 1998.

Language Note:

English

Summary:

The second edition of the popular Chromatographic Integration Methods has been completely revised and updated. Written by an expert with many years' experience with two of the world's largest manufacturers of computing integrators, it has been expanded to include a new section on validation of integrators in response to regulatory requirements for quality and validation. A new literature survey, additional diagrams and Author Index have also been added.Well illustrated and easily read, this is an excellent source book for those who wish to increase their understanding of integrators. Chromatography

Contents:

Chromatographic Integration Methods

Contents

Chapter 1 Measurements and Models

1 The Basic Measurements

Measurements and Their Use

2 Quantitation

Peak Area and Peak Height

Peak 'Volume'

Retention Time and Solute Identity

Column Hold-up Time

3 Diagnostics and System Suitability Tests

Baseline Noise

Baseline Signal Level

Peak Boundaries

Peak Width and Column Efficiency

Peak Asymmetry

Peak Resolution

Retention Time Stability

4 Results Assessment

Correct Peak Measurements

Total Peak Area

Correct Number of Peaks

Coefficient of Variation and Relative Standard Deviation

Comparison Against Standards

Trend Analysis

5 Performance Measurement

Chromatograph Utilization

Analyst Workload

Cost per Analysis

6 Chromatographic Peak Models

The Gaussian Function

The Function

Peak Height

Ratio of Area/Height

Calculation of Peak Width at Various Heights

Gaussian Peak Shape Tests

The Points of Inflection

Fractional Peak Area Bounded by Various Widths

Loss of Area from the Base of a Gaussian Peak

Gaussian Peak Maximum as an Approximate Parabola

The Exponentially Modified Gaussian Function

Practical Application of the EMG Function

EMG Peak Shape Tests

7 Statistical Moments of a Chromatographic Peak

Zeroeth Moment, m0

First Moment, m1

Second Moment, m2

Third Moment, m3

Fourth Moment, m4

Higher Odd Moments

Higher Even Moments

Measurement of Peak Moments

Practical Disadvantages and Uses

8 Manual Peak Area Measurement

Height X Width at Half Height

The Condal-Bosch Area

Peak Area by Triangulation

Manual Measurement of Asymmetric (EMG) Peaks

9 References

Chapter 2 Errors in Peak Area Measurement

1 Accuracy and Precision

Accuracy

Precision

Inaccuracy and Uncertainty.

Repeatability

Reproducibility

Random Errors

Systematic Errors

Spurious Errors

Causes of Imprecision

Causes of Inaccuracy

Precision of Integrator Measurements

2 Accurate Representation of the Solute Profile

Additivity of Signals

Negative Detector Signals

Electronic Peak Distortion

3 Peak Area and Solute Quantity

Mass and Flow Sensitive Detectors

Flow Sensitive Detectors

Mass Sensitive Detectors

Detector Overload

Linearity

Detector Non-linearity

Column Non-linearity

Electronic Noise and Drift

4 Sources of Peak Measurement Error

Hardware Errors

Noise

Noise and Frequency

Short-term Noise

Long-term Noise

Drift

Errors Created by Noise

Signal-to-noise Ratio: The Smallest Measurable Peak

Limits of Detection and Quantitation

A 'Good Baseline'

Errors Created by Baseline Drift

Drifting Baseline and Peak Measurement

Baseline Drift and Retention Time

Reduced Detector Operating Range

Some Preliminary Conclusions

Errors of Incomplete Peak Resolution

Height of a Fused Peak

Perpendicular Separation

Effect of Overlap on Area Measurement Accuracy

Error Correction Strategies

Error Propagation through Overlapping Groups

Peak Overlap and Calibration

Tangent Skim Errors

Errors of Perpendicular/Tangent Transition

Overlapping Peaks on Sloping Baselines

Multiple Fused Peaks

Mathematical Deconvolution of Overlapping Peaks

The Isomer Test

Errors from Peak Asymmetry

Asymmetry and Peak Tailing

Asymmetry and Base Broadening

Asymmetry and Manual Peak Measurement

Unequal Asymmetry

The Achievement of Accuracy in Chromatographic Analyses

Peak Area vs. Peak Height

User Surveys

5 References

Chapter 3 Manual Measurement of Peaks

1 Representation of the Detector Signal by Chart Recorder

Slow Response Time.

Non-linear Signal Response

Pen Head Damping

Amplifier Noise

Manual Measurement of Noise

Dead Band

Chart Motor Control

Attenuator Accuracy

2 Measurement Strategies

Counting Squares

Cutting and Weighing

Planimeters

3 Measurements based on a Peak Model

Pencil and Rule Methods

Measurement of Peak Height

Height vs. Area Measurements

Triangulation

Peak Height X Width at Half Height

Condal-Bosch Variation

The Foley Variations

Measurement of Overlapping Asymmetric Peaks

Peak Shape Tests

4 Errors of Manual Measurement

Optimum Peak Shape

Advantages and Disadvantages of Manual Peak Measurement

Chapter 4 Digital Integrators

1 A Brief History of Integrators

Strip Chart Recorder Techniques

Electromechanical Counters

Electronic Integrators

TTL Instruments - The First Electronic Integrators

Microprocessor-based Integrators

Integrators with Printer Plotters

The Impact of the Microcomputer

2 Current Integrator Status

Standard Integrator Specification

Integrator Files

Analysis Parameters for Peak Measurement

Peak Width

Slope Sensitivity or Detection Threshold

Baseline Drift Tolerance

Time to Double

Minimum Area or Height Threshold

Analysis Duration

Integrate Inhibit

Forcing Tangent or Perpendicular Separation

Forcing Baseline Detection

Horizontal Baseline Projection

Inverting Negative Peaks

Instrument Control and Communications

Sample Management, Calculations and Calibrations

Peak and Solute Identity

Relative Retention Times

Standard Calculations

Area% or Normalization

Internal Standard

External Standard

Sample Scheduling

Calibration

Report Preparation and Output

Trends

Report Distribution

3 Validation of Integrators

The Integrator as a Diagnostic Tool.

Specification, Installation, Operational, Performance Qualification

Integrator Specification and Selection (SQ)

Installation Checks (IQ)

Operational Qualification (OQ)

Validation and Calibration: The Difference

Records

Performance Qualification (PQ): Regular Testing of the Integrator

Logging Results

Validation of Software

4 Standard Chromatograms

Creation of Standard Chromatograms

Computer-based Standard Chromatograms

Specification of Standard Chromatograms

Creation of Synthetic Chromatograms

Baselines

Traceability of Synthetic Chromatograms

Chapter 5 Digital Measurement of Peak Areas

1 Signal Sampling

Analogue to Digital Conversion

Voltage to Frequency Conversion

Dual Slope, Integrating A/D Conversion

Resolution of A/D Converters

Auto-ranging of A/D Converters

Data Sampling Frequency

Sampling Frequency and Integrator Manufacture

Sampling Frequency and Data Processing Algorithms

Data Bunching

Baseline Bunching

Estimating the A/D Sampling Frequency and Bunch Size

Data Bunching and the Peak Width Parameter

Peak Width Parameter and Analysis Reprocessing

Peak Sampling Synchronization

Rounding or Truncation Errors

Aperture Time Jitter

2 Filtering and Smoothing the Chromatographic Signal

Filtering

Smoothing

Electronic Filters

Sampling Frequency and Mains Coupling

Smoothing Techniques

Digitizing and Integrating

Bunching

Moving Windows and Polynomial Curve Fitting

Optimum Filtering

Signal Subtraction

Chromatogram Plotting

Matched Filtering

3 Location and Measurement of Peaks

Finding the Peaks

Retention Time

Peak Shape Test

Properties of the Smoothed Data

Data Integrals

Baseline Fluctuations and Slope Sensitivity

Programming Slope Sensitivity.

Slope Sensitivity and Representative Baseline

Updating Peak Width and Slope Sensitivity during Analysis

Location of the Limits of Integration

Small Peak Filtering

Location of Peak End

Measurement of Peak Area

Baseline Convention

Measurement of Retention Time

Measurement of Two Unresolved Peaks

Measurement of Individual Peak Areas

Peak Measurement Diagnostics

Measurement of Fused Groups

Shoulders

Measurement of Tangent Peaks

Tangent Skimmed Groups

Small Peaks between Larger Ones

Tangents on Tangents

4 Baselines, A More Detailed Discussion

Baseline Drift Limit

False Starts

Formulating a Baseline Definition

Mis-timing 'Start' and 'End'

End of 'Integrate Inhibit'

Forcing Baseline

Incorrect Programming of Baseline Drift Tolerance

Fused Tangent Measurement

Single Peaks on a Rising Baseline

Valleys Between Fully-resolved Peaks

Negative Dips and Constructed Baselines

Assigning Baseline Beneath the Whole Chromatogram

Valley-Valley Skim

5 Conclusions

6 References

Author Index

Subject Index.

Notes:

Description based upon print version of record.

Includes bibliographical references and indexes.

ISBN:

9781847550514

1847550517

OCLC:

225419263