Toward standardizing deuterium content reporting in hydrogen exchange-MS.

Area of Science:

• Analytical Chemistry
• Biochemistry
• Mass Spectrometry

Background:

• Accurate dispensing is crucial for reproducible hydrogen exchange mass spectrometry (HX-MS) experiments.
• Variations in deuterium incorporation can arise from dispensing inconsistencies.
• Existing methods may not fully address systematic and random dispensing errors across different deuterium levels.

Purpose of the Study:

• To introduce a novel method for monitoring and correcting dispensing ratios in HX-MS labeling reactions.
• To harmonize HX-MS data obtained with variable deuterium oxide (%D2O) compositions.
• To identify and quantify the impact of dispensing errors on measurement precision.

Main Methods:

• Quantification of relative signal intensities from heavy and light caffeine standards to determine a correction factor for deuterium levels.
• Application of the correction factor to harmonize data across experiments with varying %D2O.
• Detection and correction of systematic and random dispensing variability.

Main Results:

• The method effectively corrects for systematic and random dispensing errors in HX-MS.
• Dispensing variability can be detected and corrected to a common value, regardless of %D2O composition.
• Random dispensing error can be the limiting factor for high-quality signal measurements in HX-MS.

Conclusions:

• The developed dispensing control method is an effective tool for monitoring measurement precision in HX-MS.
• Accurate dispensing is essential for reliable quantitative analysis in HX-MS.
• This method enhances the robustness and reproducibility of HX-MS data.