Sepra C18 sorbent was selected from all commercially available C18 sorbent materials owing to its high carbon load, its full endcapping (minimizing the residual silanol group activity and ensuring the separation selectivity based on analyte hydrophobicity), and its availability as a bulk material. The concentration and total volume of the suspension were optimized to yield conditions favorable for lipid removal whilst maintaining maximum recovery of the other LMWMs. A value of 16 mg/mL was determined to be optimal for liquid handling purposes, with more concentrated suspensions becoming too dense and non-fluid. A 1:3 sample-to-solvent ratio (accounting for the sorbent volume) was used to facilitate solvent-based protein removal at the same time as lipid depletion. The optimal conditions were 650 µL of suspension volume for a 200 µL sample (or 325 µL suspension volume / 100 µL sample).