The pure rotational spectrum of glycolaldehyde isotopologues observed in natural abundance

► The rotational spectrum of glycolaldehyde has been recorded up to 40 GHz. ► Transitions from the 13C, 18O, and D substituted isotopologues were observed. ► Transitions from HCOCH218OH are reported for the first time.► A Kraitchman analysis was performed to determine the glycolaldehyde structure.