Abstract: A mechanical holder that provides for a confined sampling region for extraction and removal of chemical substances contained in a dried blood spot or other spot of sample is described herein.

Abstract: Methods and systems for extraction of analytes from samples for analysis using mass spectrometers are described herein.

Abstract: A liquid chromatography/mass spectrometry system includes a chromatographic column through which an effluent passes, wherein the effluent comprises a plurality of analytes that correspond to a plurality of chromatographic peaks and an eluent; a post-column splitter having at least two output ports through which the effluent of the column is split to at least a first portion and a second portion; a mass spectrometer configured to receive the first portion from a first of the output ports for analysis; and a tube connected to a second of the output ports configured to prevent substantial evaporation of the eluent in the second portion until undergoing mass spectrometry. The second portion has a plurality of separated analytes corresponding to at least two chromatographic peaks. A method of using the system is also disclosed.