Rapid Quantitative Determination of Blood Propofol Concentration throughout Perioperative Period by Negative Photoionization Ion Mobility Spectrometer with Solvent-assisted Neutral Desorption

Abstract Rapid and quantitative determination of blood propofol concentration is important for anesthesiologists to accurately control intraoperative propofol dose, timely monitor physiological statuses of patients and greatly improve the safety of surgery. Herein, a dopant-assisted negative photoionization ion mobility spectrometer with the optimized ionization region structure and the three-way inlet design was developed, increasing the generation ratio of the reactant ions O2-, and improving the ionization efficiency of propofol molecules. Besides, the addition of methanol-anisole solution during injection promoted the neutral desorption of propofol in blood, further improving the detection sensitivity by an order of magnitude, eliminating any sample pretreatment and effectively reducing the single analysis time to less than 1 min compared to the previous article. The dual calibration quantitative method, i.e. the method of calibrating the O2- concentration and the sample concentration changes during the entire process of detecting propofol through the integral value of M·O2- and the maximum signal intensity of O2-, successfully achieved accurate quantification of blood propofol. And the linear calibration curve of propofol was obtained with the range of 0.1 to 15 ng μL-1 and with the limit of detection of 0.03 ng μL-1, which was fulfilled to conduct propofol determination throughout the perioperative period. Finally, this method was applied to clinically measure the blood propofol concentration in patients newly regained consciousness with concentrations ranging from 0.2 ng μL-1 to 3 ng μL-1, and it turned out that the older patient had the lower propofol concentration in blood.