Related Experiment Video
Updated: May 12, 2026

Single-throughput Complementary High-resolution Analytical Techniques for Characterizing Complex Natural Organic Matter Mixtures
Published on: January 7, 2019
Determination of carboxylic SWCNTs in river water by microextraction in ionic liquid and determination by Raman
A I López-Lorente1, B M Simonet, M Valcárcel
1Department of Analytical Chemistry, University of Córdoba, E-14071 Córdoba, Spain.
Abstract:
The paper proposes a simple approach for the preconcentration of carboxylated single-walled carbon nanotubes and their determination in river water samples. The method is based on a microliquid-liquid extraction into an ionic liquid (bmim PF6) in the presence of a cationic surfactant (CTAC). 10 μL of the ionic liquid phase are microfiltrated by using a home-made filtration device having a small diameter. The membrane was of cellulose with a pore size of 5 μm. Finally, the carbon nanotubes retained in the membrane are directly analyzed by Raman spectroscopy, which allows their direct characterization and quantification. The limit of detection was 0.050 mg L(-1). The precision, for a 1.4 mg L(-1) concentration of carbon nanotubes, is 3.2%.
Related Concept Videos
Raman Spectroscopy: Overview
However, a small fraction of the scattered light exhibits a frequency shift due to the exchange of energy between the incident photons and the...
Spectroscopy of Carboxylic Acid Derivatives
In the...
IR and UV–Vis Spectroscopy of Carboxylic Acids
However, the stretching absorptions for the C=O bond vary depending on the structure of carboxylic acids. The C=O bond of the free carboxylic acids shows a higher stretching frequency, 1760 cm−1, while H-bonded carboxylic acids (dimers) exhibit stretching absorptions at a lower frequency, 1710 cm−1. The C=O bond of the...
Raman Spectroscopy Instrumentation: Overview
The monochromatic laser source, typically using visible or near-infrared radiation, generates a highly focused beam of light. This light interacts with the molecules of the sample, scattering some of the light. Liquid and gaseous samples are usually tested in ordinary glass capillaries, while solids can be analyzed as powders packed in capillaries or as potassium...

