Improving the double quantum filtered COSY experiment by “Moving Tube” NMR

► 2D NMR spectra with a nearly 5 ft length, 5 mm OD NMR tube are shown. ► Different phase cycle steps are conducted on different vertical sample volumes. ► Sensitivity is improved, and rapid pulsing artifacts are removed. ► With long T1 or limited solubility, MT NMR may be of great benefit.