A Demonstration of Principal Component Analysis for EPR Spectroscopy: Identifying Pure Component Spectra from Complex Spectra

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• 作者：Oliver Steinbock ; Bettina Neumann ; Brant Cage ; Jack Saltiel ; Stefan C. Mü ; ller ; and Nar S. Dalal
• 刊名：Analytical Chemistry
• 出版年：1997
• 出版时间：September 15, 1997
• 年：1997
• 卷：69
• 期：18
• 页码：3708 - 3713
• 全文大小：314K
• 年卷期：v.69,no.18(September 15, 1997)
• ISSN：1520-6882

文摘

The application of principal component analysis (PCA)with self-modeling (SM) is extended to electron paramagnetic resonance (EPR) spectroscopy. Our approachdevelops a novel constraint in the SM procedure. Thisconstraint relies on the mirror symmetry around the EPRpeak position, a condition that is well satisfied by mostparamagnetic compounds at the usual EPR measurementfrequencies (9-10 GHz, the X-band). Examples considered are two- and three-component systems consisting ofaqueous solutions of paramagnetic ions that exhibitdistinct but overlapping spectra: Cu²⁺ (single peak),Mn²⁺(sextet), and VO²⁺ (octet). The results show thatthe PCAtechnique is capable of reproducing the correct numberof components and reconstructing spectra in good agreement with control measurements. Other spectroscopyareas to which the symmetric peak constraint should beapplicable include NMR, NQR, and ICR.