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In order to evaluate the utility of copper surfaces as spray initiators for mass spectrometric ionization sources, it is necessary to establish how efficient and reproducible the methodology is. To do this, a superhydrophobic and bare copper surface were used to ionize the singly and doubly charged peptides, bradykinin and leucine-enkephalin spiked with substance P as an internal standard, respectively. Both treated and bare copper surfaces were cut to 90, 60, and 30° angles. Calibration curves were constructed for both peptides on a superhydrophobic surface using covalently bonded trichloro(1H, 1H, 2H, 2H-perflourooctyl)silane-treated copper, and bare copper surface. The highest sensitivity for all peptides was observed using a 30 or 60° tip with the silane-treated copper. Limits of detection and quantitation for the 60° silane-treated surface for bradykinin were 6.01 × 10−3 μM and 2.00 × 10−2 μM respectively, with a R2 of 0.9959. Limits of detection and quantitation for the 30° silane-treated surface for leucine-enkephalin were 3.28 × 10−2 μM and 1.09 × 10−1 μM respectively, with a R2 of 0.9993. Image 1 • Copper surfaces were used as spray initiators similar to paper spray ionization. • Surfaces are reusable, have fixed geometry, and can be functionalized, and require minimal solvent to initiate a spray event. • Metalspray ionization was used to test sensitivity between bare copper and modified copper surfaces. • Copper was functionalized with trichloro(1 H , 1 H , 2 H , 2 H -perflourooctyl)silane to create a superhydrophobic surface. • Superhydrophobic surface displayed greater sensitivity and lower limits of quantitation compared to bare copper surface. [ABSTRACT FROM AUTHOR]