Question

In DNA and RNA, nitrogen atom is present in the ring system. Can Kjeldahl method be used for the estimation of nitrogen present in these? Give reasons.

Answer 1

In DNA and RNA nitrogen is present in heterocyclic base and also present in ring not as a substituent. Therefore, nitrogen present in ring cannot be converted into $(N{H}_4{)}_{2}S{O}_4$. Hence, cannot be estimated by Kjeldahl method.