Volumetric absorptive microsampling: Current advances and applications
Recently, volumetric absorptive microsampling (VAMS) has been introduced for the sampling of biological fluids, and more particularly whole blood, on a porous hydrophilic tip. VAMS enables the collection of small, accurate and precise blood volumes (10 or 20 μL) regardless of the hematocrit. After drying, the samples can be stored or directly analyzed. The stability of various compounds in dried samples supported on VAMS tips varies from one day to a few months at room temperature, and increases at lower temperatures. The complete tip is used during a simple and straightforward sample preparation. Compounds can be extracted with a variety of solvents, and thereafter directly analyzed. A design of experiments is recommended to determine the optimal extraction conditions for a reproducible recovery. The recovery of compounds might be influenced by the hematocrit.
In the last two years, various pharmacokinetic and therapeutic drug monitoring studies have been conducted with VAMS. This review covers the general aspects related with the use of VAMS and its applicability is demonstrated through examples.