Aim:Multiplexed, high-throughput analysis facilitates therapeutic drug monitoring.
14 drugs with various physico-chemical properties were quantitated in dried blood
microsamples.Methods:Analytes were extracted employing eight solvent compositions
and seven extraction methods. The applicability of liquid serum, dried serum and dried
whole blood calibrators was investigated.Results:High recoveries were attained. Calibration
using dried serum yielded lowest total error. Reducing sample hematocrit caused outstanding
elevations in recovery of analytes with high polarity or affinity to erythrocytes.
9-day analyte stability was demonstrated.Conclusion:Based on the analysis of spiked
samples, multiplexed testing of drugs in dried blood microsamples seems feasible,
but with analyte-dependent method performance. Dried serum calibration allows the
adaptation of serum-based workflows. Further evaluation using real-life specimens
is needed.
