Spectroscopy Chromatography PhysChem Naming Drawing and Databasing Enterprise Solutions Software for Interactive Curve Resolution using SIMPLISMA Andrey Bogomolov, Michel Hachey, and Antony Williams

Spectroscopy Chromatography PhysChem Naming Drawing and Databasing Enterprise Solutions SIMPLISMA is…  SIMPLe-to-Use Intuitive  Interactive Operator is involved in the process  Self-modeling No prior information is required  Mixture  Analysis

Spectroscopy Chromatography PhysChem Naming Drawing and Databasing Enterprise Solutions Willem Windig SIMPLISMA Reference: [1] W. Windig and J. Guilment, Anal. Chem. 65 (1991), 1425.

Spectroscopy Chromatography PhysChem Naming Drawing and Databasing Enterprise Solutions SIMPLISMA is a Multivariate Curve Resolution Algorithm  Extract pure component spectra from a series of spectroscopic observations of a mixture while the component concentrations vary  Obtain component concentration profiles for processes evolving in time  Detect the number of mixture components

Spectroscopy Chromatography PhysChem Naming Drawing and Databasing Enterprise Solutions General Curve Resolution Problem assumptions

Spectroscopy Chromatography PhysChem Naming Drawing and Databasing Enterprise Solutions Curve Resolution and PCA

Spectroscopy Chromatography PhysChem Naming Drawing and Databasing Enterprise Solutions Practical Applications  Qualitative characterization of unknown mixtures  Interactive process monitoring  Studying chemical reactions’ kinetics and mechanisms  Obtaining equilibrium constants  Resolving co-eluting signals in hyphenated chromatography (HPLC/DAD)  Quantitative analysis (calibration is required)

Spectroscopy Chromatography PhysChem Naming Drawing and Databasing Enterprise Solutions Self-Modeling Curve Resolution Algorithms  Evolving Factor Analysis (EFA)  Window/Subwindow Factor Analysis (WFA/SFA)  Iterative Target Transformation Factor Analysis (ITTFA)  Rank Annihilation Factor Analysis (RAFA)  Direct Exponential Curve Resolution Algorithm (DECRA) by W. Windig  and more…

Spectroscopy Chromatography PhysChem Naming Drawing and Databasing Enterprise Solutions Self-Modeling Basic Steps (Factor-Based Methods)  Deducing the number of components (PCA)  Obtaining initial curve estimates  Iterative improvement using system- specific constraints

Spectroscopy Chromatography PhysChem Naming Drawing and Databasing Enterprise Solutions SIMPLISMA is a Purity-Based Approach  A pure variable represents the component concentration profile  Find a pure variable for each component  Solve for the component spectra by means of regression  How to find pure variables?

Spectroscopy Chromatography PhysChem Naming Drawing and Databasing Enterprise Solutions Purity Function  Purity Function  Mean  Standard Deviation

Spectroscopy Chromatography PhysChem Naming Drawing and Databasing Enterprise Solutions Purity-Corrected Standard Deviation

Spectroscopy Chromatography PhysChem Naming Drawing and Databasing Enterprise Solutions Overestimated Purity Problem

Spectroscopy Chromatography PhysChem Naming Drawing and Databasing Enterprise Solutions Overestimated Purity Problem  Purity tends to the infinity when the mean approaches zero  Offset  serves to compensate for this effect  Offset is usually defined as % of the mean

Spectroscopy Chromatography PhysChem Naming Drawing and Databasing Enterprise Solutions Deducing the Number of Components  Shape of Residuals  Shape of the Resolved Curves  Shape of Purity and Purity-Corrected Standard Deviation Spectra  TSI vs LSQ plot  Cumulative %Variance  IND Function

Spectroscopy Chromatography PhysChem Naming Drawing and Databasing Enterprise Solutions SIMPLISMA Result

Spectroscopy Chromatography PhysChem Naming Drawing and Databasing Enterprise Solutions SIMPLISMA with 2 nd Derivative  The algorithm assumes that each component has pure variable  Often, in real-world mixtures this requirement is not met  Inverted 2 nd derivative may help!

Spectroscopy Chromatography PhysChem Naming Drawing and Databasing Enterprise Solutions Live Data Example

Spectroscopy Chromatography PhysChem Naming Drawing and Databasing Enterprise Solutions Advantages of SIMPLISMA  Interactive: unlike black-box algorithms, lets a human interfere  Intuitive: spectrum-like curves are easily interpreted by spectroscopists  Fast: does not perform time- consuming iterative improvements  Flexible: does not use prior assumptions about spectral and curve shapes

Spectroscopy Chromatography PhysChem Naming Drawing and Databasing Enterprise Solutions Limitations and Workarounds  Real purity is unknown => assess purity by other algorithms  No variance—no component => more experiments to make it vary  Too complex data => try to split

Spectroscopy Chromatography PhysChem Naming Drawing and Databasing Enterprise Solutions CONCLUSION  SIMPLISMA is a curve resolution program designed for use by spectroscopic experts  Commercial implementation has been transformed into a chemical software interface  Therefore, the hurdles to widespread usage have been overcome!

Spectroscopy Chromatography PhysChem Naming Drawing and Databasing Enterprise Solutions Acknowledgments  Willem Windig for the invention  Eastman Kodak for licensing the SIMPLISMA algorithm  Yuri Zhukov and Alexey Pastutsan, the ACD/Labs programmers  Antony Williams and Michel Hachey, colleagues and co-authors