Self-organization of stearic acid salts on the hemispherical surface of the aqueous subphase allows functionalization of matrix-assisted laser desorption/ionization mass spectrometry target plates for on-plate immobilized metal affinity chromatography enrichment

•Thin films of metal stearates were obtained on a hemispherical surface of a droplet.•Collapse of resulting films occurred on a solid substrate.•These structures can be obtained directly on a spot of a MALDI target plate.•Lanthanum stearate-based structure represented a promising metal-affinity sorbent.