Fig. 2.

Glyceraldehyde detected in simulated precometary organic residues. Identification of glyceraldehyde as O-pentafluorobenzyl (R) oxime bis(trimethylsilyl) ether (PFBO-TMS) in laboratory organic residues using multidimensional gas chromatography. The corresponding external glyceraldehyde standard shows identical retention times and ¹²C isotopic signatures in its mass spectra. The mass fragmentation reveals that glyceraldehyde formed in the residue is entirely composed of ¹³C-isotopes provided by the ¹³CH₃OH reactant present in the original ice mixture. Note that all aldehyde derivatives, except formaldehyde PFBO, can form syn (Z) and anti (E) stereoisomers of the oximes because the carbon nitrogen double bond (imine) formed during derivatization prevents rotation.