Amongst the following Kjeldahl’s method can’t be used for 

I.${\mathrm{PhNO}}_2$ 

II.Ph-N=N-Ph 

III.PhNHCOPh  

 IV.

VI

VII. ${\mathrm{PhNH}}_2$ 

VIII. Acetone 

IX. Nitro Ethane  

X. Urea

This method is not applicable to compound containing N atom in nitro$\left.(-{\mathrm{NO}}_2\right)$, azo compounds $(-N=N-)$, and N atom present in ring.

I, II, IV, V, VI, VIII, (It is a keto compound which does not have N atom). Compounds are not used for the quantitative estimation of N in Kjeldahl’s method.