41. Which of the following statements concerning extraction is INCORRECT?
(A) The recovery of the extraction is defined as the ratio of the instrument signal after extraction to the signal before extraction.
(B) Extraction can effectively alleviate matrix effects.
(C) Methanol is added in supercritical fluid extraction (SFE) to facilitate the extraction of polar compounds such as ibuprofen.
(D) The suitable stationary phase of a solid-phase extraction cartridge for extracting tertiary amine drugs (e.g., lidocaine) is a strong cation-exchange sorbent.
(E) Lowering the pH of the solution enhances the extraction of propionic acid (pK_a = 4.0).