PITTCON 18 - Microfluidic open interface with flow isolated desorption volume for on-line coupling of SPME devices to mass spectrometry

Congreso

Resumen *

Nowadays, technologies that efficiently integrate the sampling and sample preparation step with the direct introduction to mass spectrometry (MS) can generate a great impact in a vast variety of fields such clinical, environmental and food sciences. In this study, a novel interface that allow the direct coupling of Bio-SPME devices to MS via a microfluidic open interface (MOI) is presented. This technology, that operates under the concept of flow isolated desorption volume, consists of an open-to-ambient desorption chamber (V ? 7 µL) where the extracted analytes are delivered. Subsequently, compounds of interest are transported to the ionization source by means of the self-aspiration process intrinsic of these interfaces. Thus, any ionization technology that provides a reliable and constant suction, such electrospray ionization (ESI), atmospheric chemical ionization (APCI) or inductively coupled plasma ionization (ICP), can be hyphenated to MOI. Numerical simulations provided detailed understanding of the fluidics inside the interface and helped optimizing the system. The analytical workflow in SPME-MOI-MS consisted in the direct immersion of the SPME fiber into the matrix to extract/enrich the analytes for short times, followed by a rinsing step with water. Then, the fiber is inserted into the MOI to desorb the compounds of interest. Finally, the volume contained in the chamber is drained and the plug of analytes is moved towards the electrospray needle for ionization and direct introduction to MS. As a proof-of-concept, the fastdetermination of immunosuppressive drugs (e.g. tacrolimus, cyclosporine, sirolimus and everolimus) from 100 µL of whole blood was assessed. Limits of quantitation in the sub-ppb range were obtained for all studied compounds. Good linearity (r2 ? 0.99) and excellent precision, with (8%) and without (14%) internal standard correction, were attained for a fix-hematocrit level. Información suministrada por el agente en SIGEVA