Which of the following nitrogen-containing compounds does not give Lassaigne's test?

The Lassaigne's extract is boiled with dilute $HNO_3$ before testing for halogens because,

Lassaigne's test for nitrogen is negative for which compound?

$A$ solution of $m-$chloroaniline,$m-$chlorophenol and $m-$chlorobenzoic acid in ethyl acetate was extracted initially with a saturated solution of $NaHCO_3$ to give fraction $A$. The left over organic phase was extracted with dilute $NaOH$ solution to give fraction $B$. The final organic layer was labelled as fraction $C$. Fractions $A$,$B$ and $C$ contain respectively

The fusion of sodium with an organic compound containing nitrogen gives mainly:

The Middleton test is used for the detection of which element?