Kooperativer Bibliotheksverbund

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Format: 1 online resource (221 p.)

Edition: 2nd ed.

ISBN: 1-84755-051-7

Series Statement: ISSN

Content: 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

Note: Description based upon print version of record. , 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 -- The 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 -- 5 References -- 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 -- Baseline Noise -- Drift -- Traceability of Synthetic Chromatograms -- 5 References -- 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 Peak Height -- 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. , English

Additional Edition: ISBN 0-85186-587-9

Additional Edition: ISBN 0-85404-510-4

Language: English