Right, let's deal with the real business--disorder.

• Ctrl+q (if the Q-peaks is not on the screen)

• Well, focus on 'C16' and 'C4BA'. There is a Q-peak-Q1 right below 'C4BA' and a Q-peak-Q12 right above of 'C16'.( the distance between the Q-peak and carbon are in the right range.

• Select Q1 and Q12>>Right click>Type>Carbon>> ISOT >>.

Note:

         if the distance between the Q-peaks and carbon is too close, the Q-peak itself may not represent as a atom. if the distance between the Q-peaks and carbon is too far away, the Q-peak itself may be is a atom.

Proceed if you are end with non chemical sense molecule