1. What is Monoisotopic Mass?

The monoisotopic mass is the exact mass of a molecule calculated using the mass of the most abundant naturally occurring isotope of each element. It's particularly important in high-resolution mass spectrometry.

2. How Does the Calculator Work?

The calculator uses the sum of exact isotope masses:

Where:

• Each element's contribution is its most abundant isotope mass multiplied by its count in the formula
• Supported elements: H, C, N, O, P, S, F, Cl, Br, I

3. Importance in Mass Spectrometry

Details: Monoisotopic mass is crucial for accurate mass measurements in mass spectrometry, enabling precise molecular identification and elemental composition determination.

4. Using the Calculator

Tips: Enter molecular formula using standard notation (e.g., C6H12O6). Element symbols are case-sensitive (first letter uppercase, second lowercase if present).

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between monoisotopic and average mass?
A: Monoisotopic uses exact masses of most abundant isotopes, while average mass considers natural isotopic abundance.

Q2: Why is monoisotopic mass important in MS?
A: High-resolution MS can measure exact masses, allowing identification of molecular formulas based on precise mass measurements.

Q3: Which elements have significant isotopic distributions?
A: Elements like Cl, Br, and S have characteristic isotopic patterns that are useful for identification.

Q4: How accurate is this calculator?
A: It uses standard monoisotopic masses with 6 decimal places, sufficient for most applications.

Q5: Can I use this for large biomolecules?
A: While it works in principle, for very large molecules the isotopic distribution becomes more complex.