Wet chemical element analysis - method catalogue
ICP-OES:
Inductively Coupled Plasma with Optical Emission Spectrometry
| Principle: | The analyte solution is sprayed as an aerosol into an argon plasma. At temperatures of 6500 K the elements are atomized and/or ionized. The temperature is high enough to excite atoms and ions electronically so that they emit light. The resulting spectrum consisting of many emission lines is split up by an Echelle optics. The intensity of the emission lines is proportional to the concentration of the analyte. |
| Application: | Simultaneous determination of main, minor and trace elements Complete analysis of metallic compounds in lithium battery materials, metallic glasses superconductors, magnetic alloys, determination of main, minor and trace elements in Fe-, Zr- and Ti-based material |
| determination limit: | 0,01 - 1 µg/L (depends on element) |
| Accuracy: | 0,2 - 1 % relative standard deviation |
| Instruments: |
iCAP6500 DUO (Thermo Fisher Scientific GmbH) |
ICP-MS:
Inductively coupled plasma mass spectrometry
| Principle: | The elements are ionized in the plasma flame of an argon plasma and analyzed by a high resolution mass spectrometer. Methods of sample introduction into the flame are a nebulizer for liquid samples or laser ablation for solid samples. In laser ablation the sample is vaporized by pulsed laser shots and swept into the plasma by a gas flow. This enables a localized and spatially resolved analysis of solids. |
| Application: | Simultaneous determination of main, minor and trace of most elements in water based liquids (except H, C, N, O, noble gases); laterally and spatially resolved analysis of solids, depth profiles of solids, investigations on layered materials, e.g. trace analysis in carbon nanotubes and fullerenes, trace element analysis in copper plated microelectronic structures |
| Determination limit | 10E-9 - 10E-7 M in liquid samples, ng - mg/g range for solids (depends on element and matric) |
| Accuracy: | 0,5 - 5 % relative standard deviation |
| Instruments: | Element XR (Thermo Fisher Scientific GmbH) |
AAS
Atomic Absorption Spectrometry (flame and graphite furnace)
| Principle: | The analyte solution is sprayed as an aerosol either into a flame (oxygen-acetylene or nitrous oxide-oxygen) or into an electrically heated graphite furnace. At temperatures between 2000 and 3100 K the sample is vaporized and atomized. Light of a certain wavelength is passed through the flame/furnace and is adsorbed by the atomized analyte element. The required wavelength that can be adsorbed by the atomized element is emited from a hollow-cathode lamp made from the element that has to be analyzed. The AAS 6 vario (see under devices) works with a deuterium lamp for background correction. |
| Application: | Single element analysis of minor and trace components for most of the metals, e.g. Pd in Ag-based cover-material of superconductors, trace element analysis in thin layer materials, fullerenes and carbon nano tubes |
| Determination limit: | 0,2 - 100 mg/L(*) (flame) and 0.01 - 100 µg/L (*) (furnace) (depends on element) (*) concentration of analyte in solution |
| Accuracy: | about 0.5 - 5 % |
| Instruments: | AAS 6 vario (Analytik Jena AG) flame and graphite furnace |
Titrimetry
| Principle: | In a titrimetry increments of a reagent solution -the titrant- are added to the analyte until their reaction is completed. From the quantity of titrant required, the quantity of analyte in the unknown sample can be calculated. The requirements for a titrimetry reaction are to have a large constant equilibrium and to proceed rapidly. The most common titrations are based on acid-base, oxidation-reduction, complex formation or precipitation reactions. The equivalence point occurs when the quantity of added titrant comes to the exact amount necessary for stoichiometric reaction with the analyte. Actually measured is the end point, which is marked by a sudden change of a physical property, e.g. the electrochemical potential, conductivity, pH, the color of an indicator (spectrophotometric titrimetry) etc.. |
| Application: | Precise main component analysis of metals (except alkali metals), precise determination of stoichiometries and oxidation numbers, determination of concentrations of acids and bases |
| Determination limit: | about 0.5 mg |
| Accuracy: | about 0.1 - 1 % |
| Instruments: | Automatic titration systems DL 70 and DL 77 (Mettler Toledo) with several electrodes and phototrodes |
UV/VIS-Spectrophotometry
| Principle: | The analyte forms by a reaction with an organic agent a colored complex. The light absorption of the colored solution is measured at a certain wavelength in the visible or UV spectral range. The absorption is proportional to the concentration of the analyte. |
| Application: | wide application range from main and minor component analysis and also trace analysis of numerous transition metals, e.g. Fe, Co, Ni, Ti, e.g. Determination of Fe in numerous alloys e.g. hard magnetic alloys (Fe-Nd-B based) and soft magnetic alloys (Fe-Si-B), in steel, and numerous intermetallic compounds |
| Determination limit: | between 5 and 50 µg/g |
| Accuracy: | about 0.5 - 2 % |
| Instruments: | UV-VIS spectrophotometer Specord 250 (Analytik Jena AG) |