kjeldahl's method

Question

Kjeldahl's method cannot be used for nitrogen estimation in:

RankGuru · Accepted Answer

**Kjeldahl's Method** is widely used but has significant limitations.
- **Inability**: It cannot be used for organic compounds where nitrogen is part of a **Nitro group ($-NO_2$)**, **Azo group ($-N=N-$)**, or present in a **ring (like Pyridine)**.
- **Reason**: In these compounds, nitrogen does not quantitatively convert into ammonium sulfate when heated with concentrated sulfuric acid. Instead, most of the nitrogen escapes as $N_2$ gas during the digestion process, leading to inaccurate (too low) results.

Rank Guru

kjeldahl's method

Select the correct option: