In Vivo Monitoring of Quantum Dots in the Extracellular Space Using Push−Pull Perfusion Sampling, Online In-Tube Solid Phase Extraction, and Inductively Coupled Plasma Mass Spectrometry

摘要

To monitor the dynamic changes of extracellular quantumndots (QDs) in vivo in the livers of anesthetized rats, wendeveloped an automatic online analytical system comprisingnpush-pull perfusion (PPP) sampling, the establishednin-tube solid phase extraction (SPE) procedure, andninductively coupled plasma mass spectrometry (ICPMS).nThe method takes advantage of the retention of QDs ontonthe interior surface of a polytetrafluoroethylene (PTFE)ntube as a means of extracting the QDs from complicatednpush-pull perfusates. For the injected QDs present in thenliver extracellular fluid (ECF) at low picomolar levels, antemporal resolution of 10 min was required to collectnsufficient amounts of QDs to meet the sensitivity requirementsnof the ICPMS system. To the best of our knowledge,nthis study is the first to exploit the PPP technique for thencollection of QDs from living animals and PTFE tubingnas a SPE adsorbent for the online extraction of QDs andnthe removal of biological matrix prior to ICPMS analysisnof cadmium-containing inorganic nanocrystal. We confirmednthe analytical reliability of this method fromnmeasurements of the spike recoveries of saline samples;nin addition, we demonstrated the systems’ applicabilitynthrough in vivo monitoring of the time-dependent concentrationnprofile of liver extracellular QDs in living ratsnafter intravenous administration.