Automated solid-phase extraction workstations combined with quantitative bioanalytical LC/MS

An automated solid-phase extraction workstation was used to develop, charac terize and validate an LC/MS/MS method for quantifying a novel lipid-regula ting drug in dog plasma. Method development was facilitated by workstation functions that allowed wash solvents of varying organic composition to be m ixed and tested automatically. Precision estimates for this approach were w ithin 9.8% relative standard deviation (RSD) across the calibration range. Accuracy for replicate determinations of quality controls was between - 7.2 and + 6.2% relative error (RE) over 5-1000 ng ml(-1). Recoveries were eval uated for a wide variety of wash solvents, elution solvents and sorbents. O ptimized recoveries were generally > 95%. A sample throughput benchmark for the method was;approximate to 8 min per sample. Because of parallel sample processing, 100 samples were extracted in less than 120 min. The approach has proven useful for use with LC/MS/MS, using a multiple reaction monitori ng (MRM) approach. (C) 1999 Elsevier Science B.V. All rights reserved.