Calculate m/z ratios, charge states, and molecular masses for native mass spectrometry analysis. Interconvert between mass, charge, and m/z values.
Primary Result
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Secondary Calculation
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Mass per Charge Unit
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Native mass spectrometry is a technique that analyzes biomolecules in their native, folded state under non-denaturing conditions. It preserves protein complexes and non-covalent interactions, allowing measurement of intact molecular masses.
The m/z ratio is calculated by dividing the molecular mass by the charge state: m/z = (Mass + z × Adduct Mass) / z, where z is the charge state and adduct mass accounts for ionization (typically 1.0078 Da for H+).
Native MS typically produces lower charge states compared to denaturing conditions. Proteins often show charge states between +5 to +30, depending on their size, with larger proteins generally having higher charge states.
Adduct mass correction accounts for the mass of ionizing species (like H+, Na+, or NH4+) that attach to the molecule during ionization. This correction is essential for accurate mass determination from m/z measurements.
Native MS can achieve mass accuracy within 0.01-0.1% for well-resolved peaks. The accuracy depends on instrument calibration, resolution, and the complexity of the charge state distribution.
Higher charge states result in lower m/z values for the same molecule. Multiple charge states of the same molecule appear as a series of peaks with predictable m/z spacing, allowing charge state determination.