Final ProgramCPSA 2011
Science and Technology Coming Together to Make a Difference
October 3 - 6, 2011
Bucks County Sheraton Hotel
Langhorne, PA
Poster Abstract #05
Development of a bioanalytical DBS assay using a tandem quadrupole with a novel collision cell design
Waters Corporation, Milford, MA
Dried blood spots (DBS) have been used for over 20 years in neonatal testing. In DBS, a paper blotted heel or fingerprick is dried and shipped for analysis. This approach has now been applied to the field of bioanalysis in preclinical, toxicokinetic, and clinical studies. DBS' benefits include low sample volumes, improved study recruitment, toxicokinetic data from one animal, reduced animal usage, storage and transport expenses. However, the small volumes typical of the DBS samples require highly- sensitive LC/MS/MS assays. In addition, the cards can present matrix issues. Here we present the use of an UPLC/MS/MS technology for high sensitivity analysis of pharmaceutical compounds in DBS cards.
The DBS cards are available in treated and untreated formats. The antiviral-antiinfective chemicals on the treated cards can dissolve during extraction and can interfere with the analyte signal in LC/MS. In order to amend for any background signal from the card, special care should be taken during chromatographic method development. In this study, a new type of tandem quadrupole MS with a novel collision cell design was used that allowed simultaneous collection of full scan and MRM data. The data was collected for three types of blood spot cards spiked with Alprazolam.
The chromatography data shows significantly lower background signal for the untreated cards compared to the treated cards. The full scan MS data show that the treated cards have an increasingly intense ion current as the organic concentration of the LC gradient increases. This is also reflected in the response of analyte ion where the signal response is reduced with the treated cards. The Alprazolam assay was shown to be linear over the calibration range of 100pg/mL - 500ng/mL. This UPLC/MS/MS approach was used to analyse Sitamiquine from blood spots with an LLOQ of 50pg/mL and a linear dynamic range of 4 orders of magnitude. The QC data shows the low concentration QCs had RSD of 2.08 % and the highest QC a reproducibility of 3.8 %. This data shows that high sensitivity assays can be developed with good reproducibility using DBS cards and UPLC/MS/MS.
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