QQ-HSQC: a quick, quantitative heteronuclear correlation experiment for NMR spectroscopy

Quantitative heteronuclear single quantum coherence (Q-HSQC) is a variant of the HSQC experiment that provides quantitative peak areas. This is accomplished by combining signals acquired using four different INEPT delays. Consequently, the experiment requires four times as many scans as the HSQC experiment to achieve the same resolution in the indirect dimension. We have removed this drawback by modifying the Q-HSQC experiment so that signals corresponding to different INEPT delays are acquired simultaneously from different parts of the sample. This new experiment, which we call Quick, Quantitative HSQC (QQ-HSQC), has the quantitative properties of the Q-HSQC experiment but only requires as many scans as a conventional HSQC experiment.