The problem that has arisen from this large expansion is that mass spectrometry is mainly considered as a "magic box" technique, in which on one side a sample is introduced and on the other side the analytical data comes out. Thus, the basic aspects of the technique are often not well known. To overcome this, the authors present within this text some basic information for scientists and technicians working in the field of quantitative organic mass spectrometry, in particular for those who, for the first time, face all the problems arising from the development and use of a quantitative procedure.
This informative text presents basic information on:
- What instrumental approaches are available
- How to design a quantitative analysis
- How to improve specificity
- Some thoughts on calibration and data analysis
This book is mainly aimed at analytical chemists working in academic, environmental, pharmaceutical, biochemical, forensic, clinical and industrial laboratories, but is also appropriate for researchers new to the technique, e.g. biochemists, biologist, physicians and workers in pharmaceutical, food and the health sciences.
1 What Instrumental Approaches are Available.
1.1 Ion Sources.
1.1.1 Electron Ionization.
1.1.2 Chemical Ionization.
1.1.3 Atmospheric Pressure Chemical Ionization.
1.1.4 Electrospray Ionization.
1.1.5 Atmospheric Pressure Photoionization.
1.1.6 Matrix–assisted Laser Desorption/Ionization.
1.2 Mass Analysers.
1.2.1 Mass Resolution.
1.2.2 Sector Analysers.
1.2.3 Quadrupole Analysers.
1.3.1 Total Ion Current (TIC) Chromatogram.
1.3.2 Reconstructed Ion Chromatogram (RIC).
1.3.3 Multiple Ion Detection (MID).
1.5.1 MS/MS by Double Focusing Instruments.
1.5.2 MS/MS by Triple Quadrupoles.
1.5.3 MS/MS by Ion Traps.
1.5.4 MS/MS by Q–TOF.
2 How to Design a Quantitative Analysis.
2.1 General Strategy.
2.1.3 Sample Treatment.
2.1.4 Instrumental Analysis.
2.1.5 Method Validation.
3 How to Improve Specificity.
3.1 Choice of a Suitable Chromatographic Procedure.
3.1.1 GC/MS Measurements in Low and High Resolution Conditions.
3.1.2 LC/ESI/MS and LC/APCI/MS Measurements.
3.2 Choice of a Suitable Ionization Method.
3.3 An Example of High Specificity and Selectivity Methods: The Dioxin Analysis.
3.3.1 Use of High Resolution MID Analysis.
3.3.2 NICI in the Analysis of Dioxins, Furans and PCBs.
3.3.3 MS/MS in the Detection of Dioxins, Furans and PCBs.
3.4 An Example of MALDI/MS in Quantitative Analysis of Polypeptides: Substance P.
4 Some Thoughts on Calibration and Data Analysis.
4.1 Calibration Designs.
4.2 Homoscedastic and Heteroscedastic Data.
4.2.1 Variance Model.
4.3 Calibration Models.
4.3.1 Unweighted Regression.
4.3.2 Weighted Regression.
4.3.3 A Practical Example.
4.4 Different Approaches to Estimate Detection and Quantification Limits.