The extraction of dried blood spots (DBS) typically involves manual intervention. First, a small disc is punched out of the center of a dried blood spot placed on a DBS card. Following solvent extraction of the sample, it is also common to include further cleanup steps, using solid phase extraction (SPE) to improve detection limits or exchanging solvents for compatibility with subsequent chromatographic separations. Modern analytical labs are looking to automate the process to help reduce solvent usage and to increase sample throughput while ensuring the high quality of the resulting data.
In this report, the complete automation of dried blood spot analysis is demonstrated and the results evaluated. A novel, automated DBS Autosampler (DBS A) automatically inserts DBS cards into a Flow Through Desorption (FTDTM) cell in which individual blood spots are rapidly and effectively desorbed. The DBS A is integrated into a complete cleanup and analysis system using online SPE with replaceable cartridges combined with automated injection to an LC/MS/MS system. Automated DBS extraction methods for a variety of analytes from different matrices are examined along with the use of different SPE cartridge sorbents. The resulting precision and accuracy data are provided.
