Methods, apparatus, compositions, systems, and articles of manufacture useful in connection with performing offsite mass spectrometric (MS) analysis of samples are disclosed. In embodiments, library samples are arrayed on MS substrates in a blinded fashion and stability-packaged for transport to an off-site location where the MS substrate is de-packaged and MS analysis is performed, enabling off-site MS analysis without requiring transport of the sample library and without compromising the confidentiality of the library contents. Also disclosed are embodiments relating to substrates for desorbing and ionizing analytes, including kits and methods of use thereof.