Membrane Separator Interface for Mass-Spectrometric Analysis of Desflurane, Propofol and Fentanyl in Plasma and Cerebrospinal Fluid

V Yu Cherebillo,A Yu Elizarov,A V Polegaev,V N Sokolov,V I Nikolaev,V A Elokhin

doi:10.4236/ijmpcero.2015.44031

Abstract

Mass-spectrometric interface for the measurement of anaesthetic agent concentration in biological fluids (blood plasma and cerebrospinal fluid) is described. Sampling of biological fluids was performed during balanced inhalational (desflurane, fentanyl) anaesthesia and total intravenous (propofol, fentanyl) anaesthesia. The described method for drug concentration measurement in biologic fluids does not require long-term sample processing before injecting the sample into mass-spectrometer interface, in contrast to chromatographic methods. A hydrophobic membrane was used in the interface to separate anaesthetic agents from biological fluids: inhalational anaesthetic desflurane, hypnotic propofol, analgesic fentanyl. A possibility to use the interface for measurement of desflurane and propofol absolute concentration in blood plasma and cerebrospinal fluid was demonstrated for the study of blood-brain barrier (BBB) properties.

Highlights

Chromatographic-mass-spectrometric methods for the analysis of biological fluids require long-term sampleCurrently, methods exist for absolute concentration measurement of wide spectrum of organic compounds dissolved in water
Blood samples were drawn from peripheral vein (PV) and from surgical wound in the chiasmo-sellar area of the brain (CSAB) during adenomectomy of pituitary tumor
blood-brain barrier (BBB) lies between endothelial cells lining blood capillaries in the brain; the anaesthetic agent concentration in the blood from surgical wound in CSAB represents its concentration after passing through BBB

Summary

Introduction

Chromatographic-mass-spectrometric methods for the analysis of biological fluids require long-term sample. Methods exist for absolute concentration measurement of wide spectrum of organic compounds dissolved in water. These methods demonstrate high analytical potential of mass-spectrometer membrane interface. Using quadrupole mass-spectrometer, a limit of detection for drug concentration as good as 10−8 10−7, (0.1−5 μg/L) was achieved [4]. Disadvantages of membrane interfaces include longer response time compared to capillary injection directly into the ion source of mass-spectrometer, dependence of membrane characteristics on the temperature, and selectivity (transmission coefficient) for various compounds

Methods

Results

Conclusion