In the APT experiment, quaternary and methylene carbons (CH2) are phased negatively while methine (CH) and methyl (CH3) carbons are phased positively. With one experiment all the 13C NMR signals of diethyl phthalate are observed along with information about their multiplicity, allowing for the straightforward assignment of the signals.
Feel free to contact us if you have any questions about our instruments or if you want to see whether our instrument will be suitable for your chemistry!