Hematocrit-Independent Quantitation of Stimulants in Dried Blood Spots: Pipet versus Microfluidic-Based Volumetric Sampling Coupled with Automated Flow-Through Desorption and Online Solid Phase Extraction-LC-MS/MS Bioanalysis.
A workflow overcoming microsample collection issues and hematocrit (HCT)-related bias would facilitate more widespread use of dried blood spots (DBS). This report describes comparative results between the use of a pipet and a microfluidic-based sampling device for the creation of volumetric DBS. Both approaches were successfully coupled to HCT-independent, fully automated sample preparation and online liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) analysis allowing detection of five stimulants in finger prick blood. Reproducible, selective, accurate, and precise responses meeting generally accepted regulated bioanalysis guidelines were observed over the range of 5-1000 ng/mL whole blood. The applied heated flow-through solvent desorption of the entire spot and online solid phase extraction (SPE) procedure were unaffected by the blood's HCT value within the tested range of 28.0-61.5% HCT. Enhanced stability for mephedrone on DBS compared to liquid whole blood was observed. Finger prick blood samples were collected using both volumetric sampling approaches over a time course of 25 h after intake of a single oral dose of phentermine. A pharmacokinetic curve for the incurred phentermine was successfully produced using the described validated method. These results suggest that either volumetric sample collection method may be amenable to field-use followed by fully automated, HCT-independent DBS-SPE-LC-MS/MS bioanalysis for the quantitation of these representative controlled substances. Analytical data from DBS prepared with a pipet and microfluidic-based sampling devices were comparable, but the latter is easier to operate, making this approach more suitable for sample collection by unskilled persons.
Q2 Solutions , 19 Brown Road, Ithaca, New York 14850, United States.
Ruth
R
Verplaetse
Q2 Solutions , 19 Brown Road, Ithaca, New York 14850, United States.
Jack
J
Henion
D018663:Adrenergic Agents / Q000097:blood* / Q000302:isolation & purification; D001331:Automation; D002851:Chromatography, High Pressure Liquid; D059788:Dried Blood Spot Testing / Q000379:methods*; D006400:Hematocrit; D006801:Humans; D008694:Methamphetamine / Q000031:analogs & derivatives / Q000032:analysis / Q000302:isolation & purification; D044085:Microfluidics / Q000379:methods*; D018817:N-Methyl-3,4-methylenedioxyamphetamine / Q000032:analysis / Q000302:isolation & purification; D010645:Phentermine / Q000097:blood* / Q000302:isolation & purification; D052616:Solid Phase Extraction; D053719:Tandem Mass Spectrometry
D018663:Adrenergic Agents; D008694:Methamphetamine; C548233:mephedrone; D010645:Phentermine; D018817:N-Methyl-3,4-methylenedioxyamphetamine