N-[(1S,2R,3E)-2-Hydroxy-1-(hydroxymethyl)-3-heptadecen-1-yl]-hexadecanamide-13C2,d2; (2S,3R,4E)-2-N-Palmitoyloctadecasphinga-4-ene-13C2,d2; D-erythro-C16-Ceramide-13C2,d2; D-erythro-N-Hexadecanoylsphingenine-13C2,d2; D-erythro-N-Palmitoylsphingosine-13C2,d2; D-erythro-4-Ceramide-13C2,d2; N-Hexadecanoyl-D-erythro-ceramide-13C2,d2; N-Palmitoyl 4-sphingenine-13C2,d2; N-Palmitoyl-D-erythro-sphingosine-13C2,d2; N-Palmitoyl-D-sphingosine-13C2,d2; N-Palmitoylsphingosinee-13C2,d2