1. What is Mass Accuracy Calculator?

Definition: This calculator determines the mass accuracy in parts per million (ppm) between measured and theoretical masses.

Purpose: It's essential in mass spectrometry and analytical chemistry to evaluate measurement precision.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( \Delta m \) — Mass accuracy (ppm)
• \( m_m \) — Measured mass (u)
• \( m_t \) — Theoretical mass (u)

Explanation: The difference between measured and theoretical mass is normalized to the theoretical mass and scaled to ppm.

3. Importance of Mass Accuracy Calculation

Details: Mass accuracy helps validate experimental results, identify compounds, and assess instrument performance.

4. Using the Calculator

Tips: Enter both measured and theoretical masses in unified atomic mass units (u). Values must be positive.

5. Frequently Asked Questions (FAQ)

Q1: What does ppm stand for in mass accuracy?
A: Parts per million - a unit of relative measurement indicating how many parts of error exist per million parts of the theoretical mass.

Q2: What's considered good mass accuracy?
A: Typically <5 ppm for high-resolution instruments, though requirements vary by application.

Q3: Why use theoretical mass as the denominator?
A: It normalizes the error relative to the expected value, making comparisons across different masses meaningful.

Q4: Can this calculator handle negative values?
A: No, mass values must be positive, though the result can be negative (indicating measured mass is less than theoretical).

Q5: What fields use this calculation?
A: Primarily mass spectrometry, proteomics, metabolomics, and analytical chemistry.