1. What is PPM to Hz Conversion in NMR?

PPM to Hz conversion in Nuclear Magnetic Resonance (NMR) spectroscopy transforms chemical shift values from parts per million (ppm) to hertz (Hz) based on the spectrometer's operating frequency. This conversion is essential for comparing spectra from different NMR instruments.

2. How Does the Calculator Work?

The calculator uses the NMR frequency conversion formula:

Where:

• \( PPM \) — Chemical shift in parts per million
• \( Spectrometer Frequency \) — Operating frequency of the NMR instrument in MHz
• \( Hz \) — Chemical shift in hertz

Explanation: The formula converts the dimensionless ppm scale to absolute frequency units, allowing direct comparison between different NMR spectrometers.

3. Importance of Chemical Shift Conversion

Details: Converting ppm to Hz is crucial for accurate spectral analysis, instrument calibration, and comparing data from NMR spectrometers with different magnetic field strengths.

4. Using the Calculator

Tips: Enter chemical shift value in ppm and spectrometer frequency in MHz. Both values must be positive numbers for accurate calculation.

5. Frequently Asked Questions (FAQ)

Q1: Why convert ppm to Hz in NMR?
A: PPM values are field-independent, while Hz values are field-dependent. Conversion allows comparison of spectra from different NMR instruments.

Q2: What is the typical range for NMR frequencies?
A: Common NMR frequencies range from 60 MHz for teaching instruments to 1200 MHz for high-field research spectrometers.

Q3: How does magnetic field strength affect the conversion?
A: Higher field strength (higher MHz) results in larger Hz values for the same ppm chemical shift, providing better spectral resolution.

Q4: Can I use this calculator for different nuclei?
A: Yes, the conversion formula applies to all NMR-active nuclei (¹H, ¹³C, ¹⁵N, etc.) using their respective spectrometer frequencies.

Q5: What are common chemical shift ranges?
A: For ¹H NMR, typical chemical shifts range from 0-12 ppm; for ¹³C NMR, from 0-220 ppm.