Automation of in-tip solid-phase microextraction in 96-well format for the determination of a model drug compound in human plasma by liquid chromatography with tandem mass spectrometric detection

Studies using in-tip solid phase microextraction (in-tip SPME) in a 96-well plate format are conducted to investigate the feasibility of SPME automation. The sample preparation process, including extraction and desorption, was fully automated and coupled with currently commercially available automated liquid handling systems. Several process parameters including extraction time and speed, and desorption time were investigated. An LC-MS/MS method has been developed and validated to determine the levels of a drug compound (MK-0533) in human plasma that demonstrates the suitability of this new approach. The developed method has a lower limit of quantitation (LLOQ) of 5 ng/mL when 0.25 mL of human plasma is processed and is validated in the concentration range of 5-2000 ng/mL. The successful application of the assay in clinical sample analysis indicates that in-tip SPME can be easily automated and has great potential to be used for high throughput quantitative determination of drugs in pharmaceutical industry. (C) 2009 Elsevier B.V. All rights reserved.