Use of conventional bioanalytical devices to automate DBS extractions in liquid-handling dispensing tips.

BACKGROUND: Conventional liquid-handling devices were employed, along with an improved punching device, to semi-automate dried blood spot (DBS) extraction of alprazolam, α-hydroxyalprazolam and midazolam from human whole blood. Liquid-handling devices were used to add internal standard to the DBS cards and to extract the analytes from the DBS, in order to be analyzed by HPLC-MS/MS. RESULTS: The technique was shown to be accurate (±12.0%) and precise (10.3%) across the dynamic range of the assay. CONCLUSION: The semi-automated extraction reduced sample preparation time by more than 50% when compared with more conventional DBS manual extraction methods.

Development and validation of an HPLC-MS/MS method for the analysis of dexamethasone from pig synovial fluid using dried matrix spotting.

BACKGROUND: Dried matrix spot techniques were employed to validate an HPLC-MS/MS assay for the determination of dexamethasone in clear Yorkshire pig synovial fluid using 15 µl of sample. We have adopted the term dried matrix spot to indicate that the techniques used for dried blood spots can be applied to nonblood matrices. The dried matrix spot method employs a color-indicating process developed at Alturas Analytics that enhances the ability to analyze transparent fluids spotted onto collection paper by allowing the analyst to visually verify the location of the dried sample spot. RESULTS: The method was shown to be accurate (±4.3%) and precise (14.2% at the LLOQ and ≤10.0% at all other concentrations) across the dynamic range of the assay. CONCLUSION: The method shows the potential application of dried matrix spot techniques for the analysis of transparent biological fluids.