Analytical services

Cobra Technologies supplies different analytical services either in-house or in collaboration with our partners.

Overview of analytical services:

  • Karl-Fischer
    • Coulometric and volumetric determination of (trace) amount of water in a liquid sample. A compartment contains the anode solution plus the analyte. The titration cell, which is submerged in the anode solution, contains a cathode solution. Both compartments are separated by an ion-permeable membrane. The end point is detected most commonly by a bipotentiometric method.
    • E.g. water concentrations in alcohols, ketons and esters
  • Refractive index
    • Number which indicates how light propagates/ bent through a (mixture) medium at certain wavelength. The refractive index can be seen as the factor by which the speed and the wavelength of the radiation are reduced with respect to their vacuum values: the speed of light in a medium is v = c/n, and similarly the wavelength in that medium is λ = λ0/n, where λ0 is the wavelength of that light in vacuum. This implies that vacuum has a refractive index of 1, and that the frequency (f = v/λ) of the wave is not affected by the refractive index.
    • E.g. All binary liquid mixtures with a reasonable difference in single component refractive index
  • GC (gas chromatography)
    • Chromatography in gas phase where compounds can be separated and analysed/ identified after vaporization without decomposition. The compounds passes a stationary phase which has a different retention time for different compounds. The comparison of retention times indicates the compound.
    • Eg. Almost all volatile component mixtures.
  • Gravimetric analysis
    • For the quantitative determination of a compound based on its mass. The principle behind this type of analysis is that once an compounds mass has been determined as a unique compound, that known measurement can then be used to determine the same compounds mass in a mixture, as long as the relative quantities of the other constituents are known. An analytical balance with a readability of 0,0001 gram is mostly used.
    • E.g. All components which can be analysed on mass balance, such as tar-like components (from water pipe tobacco) in Shair filter, density measurements and water.
  • Particle size with Zetasizer nano range
    • Particles and molecules from less than a nanometer in size to a few microns can be analyzed by a range of variants. The systems measure size and micro rheology using dynamic light scattering, and electrophoretic mobility using electrophoretic light scattering, and molecular weight using static light scattering.
    • E.g. dispersed particles within a size range from 1-1000 nm
  • SEM (Scanning Electron Microscope) with EDX
    • A SEM produces images of a sample by scanning the surface with a focused beam of electrons. The electrons interact with atoms in the sample, producing various signals that contain information about the sample’s surface topography and composition. The electron beam is scanned in a raster scan pattern, and the beam’s position is combined with the detected signal to produce an image. SEM can achieve resolution better than 1 nanometer.
    • EDX (Energy-dispersive X-ray spectroscopy) is an analytical technique used for the elemental analysis or chemical characterization of a sample. It relies on an interaction of some source of X-ray excitation and a sample. Its characterization capabilities are due in large part to the fundamental principle that each element has a unique atomic structure allowing a unique set of peaks on its electromagnetic emission spectrum.
  • Pervaporation dehydration
    • Pervaporation is the selective evaporation of one of the components of a liquid mixture using a membrane. The word pervaporation itself is a combination of the words permeation, the transport through a membrane, and evaporation, the phase transition from the liquid to the vapour phase. A real breakthrough in separation technology, enabling the purification of a diversity of industrial solvents.
    • E.g. dehydration of alcohols, ketons, esters or other organic liquids
  • Vapour permeation
    • Alternative to pervaporation. In this case the feed is fully vaporized.