Patent ID: 8116983

Claim:
A device for the quantitative analysis of a drug and/or a metabolite profile in a biological sample, comprising: (A) one or more wells, (B) one or more inserts located in the wells, wherein the insert comprises: (a) a support comprising a sorbent material for liquids with which the support is impregnated, and (b) at least one organic internal standard being encapsulated with a covering material protecting the internal standard from degradation and chemical reactivity prior to use, wherein the covering material comprises at least one of a micelle-forming compound, a liposome-forming compound, a polyhydroxy compound, a polymer selected from polyalkylene glycol homopolymers or copolymers or mixtures thereof, and (C) a retainer holding the insert within the well with a distance between the insert and the the walls and the bottom of the well in order to allow a free circulation of fluids around the insert.