Abstract: The invention relates to a device for the rapid simultaneous collection, and, optionally, treatment or standardization, of multiple aliquots of a liquid biological sample such as blood from a single source drop or sample portion, the device comprising device comprising a cover, a spreading layer comprising a macroporous membrane adjacent to the cover, where the spreading layer comprises a transport portion and at least one accumulation portion in fluid connection with the transport portion, and at least one collection portion in fluid connection with each accumulation portion.

Abstract: The present invention comprises methods for determining the presence, amount, or concentration of analytes of interest including Vitamin D and other secosteroids from biological samples, through derivatization, with improved speed and ease of analysis and improved sensitivity to mass spectrometry. In a preferred embodiment, the present invention comprises methods for determining the presence, amount, or concentration of analytes of interest, including Vitamin D and other secosteroids from whole human blood, through derivatization, and using a plasma collection device to facilitate collection, separation, and preparation of the sample for derivatization and analysis.

Abstract: The present invention comprises methods for determining the presence, amount, or concentration of analytes of interest including Vitamin D and other secosteroids from biological samples, through derivatization, with improved speed and ease of analysis and improved sensitivity to mass spectrometry. In a preferred embodiment, the present invention comprises methods for determining the presence, amount, or concentration of analytes of interest, including Vitamin D and other secosteroids from whole human blood, through derivatization, and using a plasma collection device to facilitate collection, separation, and preparation of the sample for derivatization and analysis.