1. What is Mass Accuracy Calculator?

Definition: This calculator determines the mass accuracy in parts per million (ppm) by comparing measured mass to theoretical mass.

Purpose: It's essential for mass spectrometry analysis, chemical measurements, and precision instrumentation.

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 by the theoretical mass and scaled to ppm.

3. Importance of Mass Accuracy

Details: Mass accuracy is crucial for identifying compounds, validating measurements, and ensuring instrument calibration in analytical chemistry.

4. Using the Calculator

Tips: Enter both measured and theoretical masses in unified atomic mass units (u). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What does ppm stand for?
A: Parts per million - a unit of relative measurement indicating 1 part in 1,000,000 parts.

Q2: What's considered good mass accuracy?
A: In mass spectrometry, <5 ppm is typically excellent, 5-10 ppm is good, and >10 ppm may need verification.

Q3: Why use atomic mass units (u)?
A: u provides a consistent scale for molecular and atomic mass measurements.

Q4: Can I use other mass units?
A: Yes, but both masses must be in the same units for accurate ppm calculation.

Q5: What causes negative ppm values?
A: Negative values occur when measured mass is less than theoretical mass, indicating potential measurement errors or different compounds.