Correcting for Incomplete Saturation and Off-Resonance Effects in Multiple-Site Saturation-Transfer Kinetic Measurements

✍ Scribed by Peter B Kingsley; W.Gordon Monahan

• Publisher: Elsevier Science
• Year: 2000
• Tongue: English
• Weight: 96 KB
• Volume: 146
• Category: Article
• ISSN: 1090-7807
• DOI: 10.1006/jmre.2000.2124

✦ Synopsis

The effects of incomplete saturation and off-resonance irradiation on nuclear magnetic resonance saturation-transfer measurements of three-site chemical-exchange rates are discussed. A new method that uses double-saturation measurements is compared with two published methods, one that uses single-saturation measurements and one that uses a single-saturation measurement and a double-saturation measurement. Several formulas are compared for measuring the exchange rate constant k DE for exchange from a detected spin D to an exchanging spin E in the presence of exchange from spin D to a competing spin C. For each method, formulas are derived with corrections for incomplete saturation or off-resonance effects, with both corrections, and with neither correction. Exact formulas are available for three exchanging sites with incomplete saturation if there are no off-resonance effects. Off-resonance corrections are imperfect even with complete saturation.