Quantitative Bioanalysis—Automated Solid-Phase Extraction

Quantitative Bioanalysis—Automated Solid-Phase Extraction 

The analysis strategy uses LC/MS/MS in combination with a 96-well disk plate SPE. The activities associated with sample preparation and analysis are decoupled to simplify troubleshooting and to allow for greater flexibility. The benefit of this off-line approach is the ability to simultaneously prepare 96 samples with SPE in 1 h, followed by the LC/MS/MS analysis on each sample. Previous approaches with individual SPE cartridges required 2-3 h. 

Sample preparation is automated for high-throughput batch processing with SPE, which is better suited for automation than other 

In this study, the LC/MS/MS analysis is 3 min, with injections occurring every 3.5 min. The previous HPLC method with fluorescence detection had a cycle time of 25 min. Thus, many opportunities exist with LC/MS/MS quantitative analyses to optimize chromatographic separations for speed. Similar to standard approaches described for open-access or metabolite identification, standard or generic methods may be usable with this application (Dear et al., 1998). 

In a period of 6h, 96 samples plus standards and quality control (QC) samples are analyzed with this method. Other assays have been performed with 2 min cycle times. Unattended analysis of six 

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Quantitative Bioanalysis—Automated Solid-Phase Extraction... 

Pharmacokinetics Quantitative bioanalysis Selected ion monitoring Selected reaction monitoring Automated off-line solid-phase extraction Automated on-line extraction Fouda et al., 1991 Wang-Iverson et al., 1992 Covey et al., 1986 Kaye et al., 1992 Allanson et al., 1996 Simpson et al., 1998 Needham et al., 1998... 

Zhang, L. Laycock, J.D. Hayos, J. Flynn, J. Yesionek, G. Miller, K.J. Automated Strategies for Protein Precipitation Filtration and Solid Phase Extraction (SPE) Optimization on the TECAN Robotic Sample Processor—Applications in Quantitative LC-MS/MS Bioanalysis, paper presented at LabAutomation 2004, February 1-5,2004, San Jose, CA. 

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