Laser ionization time-of-flight mass spectrometry for the evaluation of a local microenvironment in an emulsion

Abstract

This study verified that laser ionization time-of-flight mass spectrometry (LI-TOFMS) is applicable to the evaluation of a local microenvironment in an emulsion.

Time-Profile Measurement of an Emulsion Using Multiphoton Ionization Time-of-Flight Mass Spectrometry in Combination with a Microscope

“…Incidentally, aggregates observed in the present study were considered to not have been generated in the sample container, but to have been gradually generated as they flowed through the capillary column due to the differences in the line velocities among the small droplets. In particular, in order to set a microscope between the sample container and the TOFMS, the length of the inner capillary column in the present study was rather long (120 cm) compared with that in the previous report (40 cm), 36,37 and this resulted in promoting the generation of aggregates during flow through the capillary column during sample introduction.…”

“…Moreover, the signal intensities of toluene were found to have decreased with time during monitoring of the lower portions of an emulsion, which is where the creaming gradually occurred. Furthermore, we applied this method to our evaluation of hydrophobic and hydrophilic compounds and their extraction behavior toward oil droplets in O/W emulsions, 37 along with our analysis of the constituents that exist in W/O/W multiple emulsions. 38 For inquiries such as this, this technique confers a distinguishing ability to monitor a local microenvironment in an emulsion.…”

Online Monitoring of a Styrene Monomer and a Dimer in an Emulsion via Laser Ionization Time-of-Flight Mass Spectrometry

“…17 The online monitoring of an oil phase of oil-in-water (O/W) emulsion has only recently been achieved, where intense spikes can be read on the time profile of the peak area of the mass spectrum of an analyte. 17,18 These spikes indicate the existence of a highly concentrated oil component, which amounts to only a small oil droplet. 19 We also applied this method to the direct measurement of analytes in a water-in-oilin-water (W/O/W) multiple emulsion.…”

Application of Laser Ionization Time-of-Flight Mass Spectrometry for the Direct Measurement of a Silane Coupling Agent in Slurries

“…In addition, we also applied LI-TOFMS to the measurement of liquid samples, 34,35 including emulsions. [36][37][38][39] In the present study, we treated TiO2 nanoparticles with PTES and prepared slurry samples where PTES either remained or was removed by washing. Then, a direct mass analysis of the slurries was performed by LI-TOFMS, and we confirmed whether the remaining PTES could be detected.…”