Abstract: A new pulse sequence for noise reduction in phase sensitive HMQC experiment is proposed by setting 90°_x(¹H)-τ/2-180°_x(¹H,¹³C)-τ/2-90°_x(¹H,¹³C) and 90°_x(¹³C)-τ/2-180°_x(¹H,¹³C)-τ/2-with τ=(2J_CH)^-1 (J_CH is the one-bond coupling constant) as the preparation and the mixing schemes, respectively. The suppression of signals of protons attached to carbon-12 can be achieved in only one scan irrespective of pulse phase cycles. The proposed method provides an alternative approach for noise reduction in HMQC measurements.

Key words: HMQC, Noise reduction, Inverse detection, Phase sensitive