1. What is PPM to Hz Conversion?

The PPM to Hz conversion is essential in Nuclear Magnetic Resonance (NMR) spectroscopy. It converts chemical shifts (in parts per million, ppm) to absolute frequency differences (in Hertz, Hz) based on the spectrometer's magnetic field strength.

2. How Does the Calculator Work?

The calculator uses the simple conversion formula:

Where:

• \( PPM \) — Chemical shift in parts per million (ppm)
• \( \text{Spectrometer Frequency} \) — The operating frequency of the NMR spectrometer in MHz

Explanation: The chemical shift in ppm is multiplied by the spectrometer frequency to get the absolute frequency difference in Hz. This conversion is field-dependent.

3. Importance in NMR Spectroscopy

Details: While chemical shifts are reported in ppm (which are field-independent), many NMR experiments require knowing the absolute frequency differences in Hz, especially when setting up pulse sequences or measuring coupling constants.

4. Using the Calculator

Tips: Enter the chemical shift value in ppm and the spectrometer frequency in MHz. Both values must be valid (frequency > 0).

5. Frequently Asked Questions (FAQ)

Q1: Why convert PPM to Hz?
A: While ppm is field-independent and good for comparing spectra from different instruments, Hz values are needed for setting up experiments and measuring J-couplings.

Q2: Does this conversion depend on nucleus type?
A: No, the conversion is the same for all nuclei. However, different nuclei have different reference frequencies.

Q3: What's a typical NMR spectrometer frequency?
A: Common frequencies are 60 MHz (teaching instruments), 300 MHz, 400 MHz, 500 MHz, and up to 1 GHz for high-field research instruments.

Q4: How precise should my input values be?
A: For most applications, 2-4 decimal places for ppm and 1-2 decimal places for frequency are sufficient.

Q5: Can I use this for other types of spectroscopy?
A: The same principle applies to other forms of magnetic resonance spectroscopy, though the reference frequencies would differ.