Ice elemental composition as [X]/[Carbon] for Hydrogen, Nitrogen, Oxygen, and Sulphur as a function of protoplanetary disk radius. Peak desorption radii for selected species are indicated in the plot (vertical dashed lines). Elemental compositions of Soluble Organic Matter (SOM) obtained from the Murchison meteorite (Schmitt-Kopplin et al. 2010) and averaged Insoluble Organic Matter (IOM) (Alexander et al. 2017) are indicated (horizontal dashed lines). The desorption profiles are simulated with a first-order Polanyi-Wigner equation, variable surface coverages, and a heating rate of 1 K century⁻¹. An average protoplanetary disk temperature profile of T(r) = 200 × (r/1AU)^0.62 (Andrews & Williams 2007) is used to determine the radii.