1. What is Exact Mass?

Exact mass refers to the calculated mass of an ion or molecule determined by summing the masses of the most abundant isotopes of each element. It provides a more precise measurement than average atomic mass for mass spectrometry applications.

2. How Does the Calculator Work?

The calculator uses the exact mass formula:

Where:

• Isotopic Masses — Mass values of individual isotopes in atomic mass units (amu)

Explanation: The calculator simply sums all the isotopic mass values provided to calculate the total exact mass of the molecule or ion.

3. Importance of Exact Mass Calculation

Details: Exact mass calculation is crucial in mass spectrometry for identifying molecular formulas, distinguishing between isobaric compounds, and confirming molecular structures with high precision.

4. Using the Calculator

Tips: Enter isotopic masses as comma-separated values in atomic mass units (amu). All values must be valid numeric values representing isotopic masses.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between exact mass and average mass?
A: Exact mass uses the most abundant isotopes of each element, while average mass uses the weighted average of all naturally occurring isotopes.

Q2: Why is exact mass important in mass spectrometry?
A: High-resolution mass spectrometers can distinguish between compounds with very similar masses, making exact mass crucial for accurate molecular identification.

Q3: How precise should isotopic masses be?
A: For most applications, isotopic masses should be provided with at least 4-6 decimal places for accurate exact mass calculation.

Q4: Can this calculator handle negative values?
A: While technically possible, isotopic masses are typically positive values. Negative values would represent an unusual physical scenario.

Q5: What are common applications of exact mass calculation?
A: Pharmaceutical research, metabolomics, proteomics, environmental analysis, and forensic chemistry all rely on exact mass calculations.