Jump to main content
Jump to site search

Issue 10, 2013
Previous Article Next Article

Performance of a microfluidic device for in situ ToF-SIMS analysis of selected organic molecules at aqueous surfaces

Author affiliations

Abstract

In this study, we report new results concerning the analytical performance of a novel portable vacuum compatible device enabling in situ study of aqueous surfaces using vacuum-based surface analysis tools. The surfaces of aqueous solutions of three representative organic molecules (formic acid, glycerol, and glutamic acid) were analyzed using time-of-flight secondary ion mass spectrometry (ToF-SIMS). Their molecular signals were successfully observed. The device can be operated without interruption in vacuum for up to 8 hours, and SIMS measurements are feasible at any time in this time range. The stability testing of our device under primary ion beam bombardment shows that high fluence (6 × 1012 ions per cm2 s−1) measurements can be operated continuously for up to 30 minutes without any significant damage to the aperture. However, extra-high fluence measurements (>1 × 1014 ions per cm2 s−1) may lead to rapid boiling in the aperture, and the aqueous solutions may spread out quickly. Device reproducibility is studied for both consecutive measurements over a short period of time (e.g., 5 min) and intermittent measurements over a long time (e.g., several hours). The relative standard deviation (RSD) for molecular ion signals was determined to be less than 15% for consecutive measurements in 5 min. As to total counts, the RSD is determined to be less than 1% for each chemical compound. Higher RSDs of ±40–50% were obtained for intermittent measurements in a few hours, both acceptable for semi-quantitative analysis. In addition, the detection limits of formic acid, glycerol, and glutamic acid are estimated to be 0.04%, 0.008%, and 0.002% (weight ratio), respectively.

Graphical abstract: Performance of a microfluidic device for in situ ToF-SIMS analysis of selected organic molecules at aqueous surfaces

Back to tab navigation
Please wait while Download options loads

Supplementary files

Publication details

The article was received on 07 Dec 2012, accepted on 29 Mar 2013 and first published on 03 Apr 2013


Article type: Paper
DOI: 10.1039/C3AY26513G
Citation: Anal. Methods, 2013,5, 2515-2522
  •   Request permissions

    Performance of a microfluidic device for in situ ToF-SIMS analysis of selected organic molecules at aqueous surfaces

    L. Yang, Z. Zhu, X. Yu, S. Thevuthasan and J. P. Cowin, Anal. Methods, 2013, 5, 2515
    DOI: 10.1039/C3AY26513G

Search articles by author