Simultaneous Determination of Ropivacaine and 3-Hydroxy Ropivacaine in Cerebrospinal Fluid by UPLC-MS/MS

Abstract

In this paper, a UPLC-MS/MS method was developed for the determination of ropivacaine and its metabolite 3-hydroxy ropivacaine in cerebrospinal fluid. The cerebrospinal fluid was processed by ethyl acetate liquid-liquid extraction. The multiple reaction monitoring (MRM) mode was used for quantitative analysis by monitoring the transitions of m/z 275.3 → 126.2 for ropivacaine, m/z 291.0 → 126.0 for 3-hydroxy ropivacaine, and m/z 290.2 → 198.2 for the internal standard. Standard curves for ropivacaine and 3-hydroxy ropivacaine in cerebrospinal fluid were conducted over the concentration range of 0.2–2000 ng/mL, demonstrating excellent linearity, and the lower limit of quantification was 0.2 ng/mL. The intraday precision of ropivacaine and 3-hydroxy ropivacaine was less than 11%, while the interday precision was less than 7%. The accuracy ranged between 87% and 107%, the average extraction efficiency was higher than 79%, and the matrix effect was between 89% and 98%. The developed method was then applied to a case of suspected poisoning of ropivacaine.

Comparison of metabolic rates of ropivacaine in cerebrospinal fluid as inferred from plasma concentrations between elderly patients and young patients

“…The total concentration of ropivacaine was determined with high-performance liquid chromatography (Chen et al 2020 ; Gromov et al 2021 ) (HPLC, 2995 pump, 2996 diode array detector, Waters, USA). The HPLC column was a shim-pack C18 column (250 mm × 6 mm, 5 microns) and the pre-column was Alltech C18 (10 mm × 4.6 mm, 5 microns).…”

Towards a better understanding of idiopathic epilepsy through metabolic fingerprinting of cerebrospinal fluid in dogs

“…Generic extraction of CSF metabolites was optimized by means of a design of experiments using JMP 15 software (SAS, UK). Firstly, a literature search was performed to select the relevant factors to include in our design 18 , 57 – 64 . Secondly, an FFD was established with 19 experiments and 3 center points to assess the effect of four factors: starting volume (100 µl or 200 µl), type of solvent (50% ACN in water (A) or ACN/methanol/acetone (1/1/1) (B)), centrifugation time (5 min or 10 min) and the usage (yes/no) of a PVDF membrane filter (13 mm diameter, 0.22 µm pore size, Merck, Ireland).…”