Development and validation of LC-MS/MS method for the detection and quantification of CpG oligonucleotides 107 (CpG ODN107) and its metabolites in mice plasma.

Abstract CpG oligodeoxynucleotide 107 (CpG ODN107) could be used as a novel radiosensitizer for glioma. Herein, a novel and sensitive reversed-phase HPLC coupled with electrospray triple quadrupole mass spectrometry (LC–MS/MS) following a one-step C18 solid-phase extraction (SPE) for biological matrix removal was developed and fully validated for the determination of CpG ODN107 and its metabolites such as 5′N-1, 3′N-1, 3′N-2, and 3′N-3 in mouse plasma. The analytes were separated on an Extend-C18 analytical column (150 mm × 2.1 mm, 3.5 μm) using an eluent of acetonitrile–0.05% aqueous NH 3 (20:80, v/v) and detected by electrospray ionization (ESI) mass spectrometry in the negative multiple reaction monitoring mode (MRM). The assay was specific, and it showed a good linearity with a determination coefficient ( r 2 ) that was greater than or equal to 0.998 for CpG ODN107 and its metabolites in the biological matrices. The precision, accuracy, and relative recovery values were found to be