Newlands Press, Bioanalysis, 3(6), p. 307-318, 2014
DOI: 10.4155/bio.13.311
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Background: Dried blood spot (DBS) sampling is emerging as a valuable technique in a variety of fields, including clinical and preclinical testing of pharmaceuticals. Despite this popularity, current DBS sampling and analysis processes remain laborious and time consuming. Digital microfluidics, a microscale liquid-handling technique, characterized by the manipulation of discrete droplets on open electrode arrays, offers a potential solution to these problems. Results: We report a new digital microfluidic method for multiplexed extraction and analysis of pharmaceuticals in DBS samples. In the new method, four DBS samples are extracted in microliter-sized droplets containing internal standard, and the extract is delivered to dedicated nanoelectrospray ionization emitters for direct analysis by tandem mass spectometry and selected reaction monitoring. Conclusion: The new method allows for an order of magnitude reduction in processing time and approximately three-times reduction in extraction solvent relative to conventional techniques, while maintaining acceptable analytical performance for most drugs tested.