Development of Microwave-Assisted Hydrothermal Extraction Coupled to Ion Chromatography for Comprehensive Analysis of Chemical Composition in Intracorporeal Stone

Abstract

A convenient method based on microwave-assisted hydrothermal extraction coupled to ion chromatography was proposed for comprehensive analysis of chemical composition in biological samples. Water was used as extraction solvent and a small amount of alkali or a small volume of acid was served as modifier to improve extraction efficiency. Factors affecting extraction efficiency were investigated using multi-response optimization method on the base of the Derringer’s desirability function. Owing to the specific role of microwave irradiation, the approach could greatly shorten sample treatment time, leading to high sample throughput. The lowest limits of quantification of procedure were 0.02 mg L−1 for F−, NO3− and cations, and 0.04 mg L−1 for five anions, respectively. Recoveries ranged from 85.7 to 110.0% with the relative standard deviations in the range of 0.95–4.6%. The strategy was successfully applied to the determination of elemental species of both an inorganic and organic nature in vesical, renal, and urethral stones. Thirteen compounds in human stone were accurately diagnosed resulting from elemental speciation in calculi could be well maintained in the extraction process. The proposed protocol could achieve batch samples pretreatment and provided a powerful tool for the analysis of intracorporeal calculi, which would be very beneficial for therapy and prevention recurrence of stone-forming patient.