High‐speed gradient parallel liquid chromatography/tandem mass spectrometry with fully automated sample preparation for bioanalysis: 30 seconds per sample from plasma

Abstract

In this work, a high-throughput and high-performance bioanalytical system is described that is capable of extracting and analyzing 1152 plasma samples within 10 hours. A Zymark track robot system interfaced with a Tecan Genesis liquid handler was used for simultaneous solid-phase extraction of four 96-well plates in a fully automated fashion. The extracted plasma samples were injected onto four parallel monolithic columns for separation via a four-injector autosampler. The use of monolithic columns allowed for fast and well-resolved separations at a considerably higher flow rate without generating significant column backpressure. This resulted in a total chromatographic run cycle time of 2 min on each 4.6 x 100 mm column using gradient elution. The effluent from the four columns was directed to a triple quadrupole mass spectrometer equipped with an indexed four-probe electrospray ionization source (Micromass MUX interface). Hence, sample extraction, separation, and detection were all performed in a four-channel parallel format that resulted in an overall throughput of about 30 s per sample from plasma. The performance of this system was evaluated by extracting and by analyzing twelve 96-well plates (1152) of human plasma samples spiked with oxazepam at different concentrations. The relative standard deviation (RSD) of analyte sensitivity (slope of calibration curve) across the four channels and across the 12 plates was 5.2 and 6.8%, respectively. An average extraction recovery of 77.6% with a RSD of 7.7% and an average matrix effect of 0.95 with a RSD of 5.2% were achieved using these generic extraction and separation conditions. The good separation efficiency provided by this system allowed for rapid method development of an assay quantifying the drug candidate and its close structural analog metabolite. The method was cross-validated with a conventional liquid chromatography/tandem mass spectrometry (LC/MS/MS) assay.

Properties of Monolithic Silica Columns for HPLC

“…3,[49][50][51] An increase in the number of separated peaks per unit time can also be achieved by an increased separation speed made possible by monolithic silica columns. 52,53 This has also been shown for peptides and proteins (Fig. 8).…”

Candidate‐based proteomics in the search for biomarkers of cardiovascular disease

“…drugs (Streit et al 2002(Streit et al , 2004, drug metabolites (Kostiainen et al 2003), hormones (Tai et al 2004), and pesticides ), with excellent precision (Tai et al 2004) and very high throughput (Bakhtiar et al 2002;Deng et al 2002). In these methods, a sample is typically subjected to some form of high-throughput prefractionation (e.g.…”

Present and Future Applications of High Resolution Mass Spectrometry in the Clinic

“…Combined with a high resolution mass spectrometer a fully realized implementation of this technology would absolutely resolve the molecular formula of ions as well as fully resolve them from isobaric species in seconds. At the moment throughput is routinely increased by multiplexing parallel liquid chromatography modules to facilitate mass spectrometric detection at only the point of analyte elution 42 . LC systems require maintenance and have associated consumable costs in the form of chromatography columns and solvent.…”