Examples of chemical analysis
1. Chemical analysis of alloying elements
This order is a typical experiment of metal analysis. Representative analytical values of a bulk metal have been obtained. Gaseous analyses have been employed to obtain the content of hydrogen, carbon, nitrogen, oxygen, and sulfur in the metal sample. The other constituents (most of alloying elements) have been quantified by using inductively coupled plasma atomic emission spectrometric analysis. For example, the following analytes in cobalt-chromium-molybdenum alloys have been assayed: Co (Bal.), Cr (26.5-30.0), Mo (4.5-7.0), Ni (<1.0), Fe (<1.0), C (<0.35), Mn (<1.0), Si (<1.0), W (<0.2), P (<0.02), S (<0.01), N (<0.25), Al (<0.1), Ti (<0.1), B (<0.01) (JIS T 7402 includes these elements)。Inorganic materials (e.g., ceramics and natural ores) can also be assayed.
It is very important for researchers to notify us the purpose of quantification as follows: (1) Materials characterization (e.g., mill test report, a check on metal preparation, an analysis verification, an investigation of a commercial product, an analysis of unknown sample, etc.), (2) Compositional variations check (e.g., influence of experimental conditions, with and without treatment, etc.), and (3) Accidental contaminations (e.g., experimental contamination assessment, kinds of impurities, etc.).
Ex. Analytical results of alloying elements in JSS 602-11
tool steel of certified reference material using ICP-AES.
| Analytical value 1 | Analytical value 2 | Certified value | |
| Vanadium | 0.229 | 0.222 | 0.218 |
| Chromium | 0.369 | 0.358 | 0.366 |
| Manganese | 0.302 | 0.293 | 0.301 |
| Cobalt | <0.004 | <0.004 | ― |
| Nickel | 0.158 | 0.154 | 0.1547 |
| Molybdenum | 0.049 | 0.047 | 0.0455 |
| Tungsten | 3.69 | 3.59 | 3.57 |
2. Purity (Quantification of trace impurities)
It is very difficult to obtain reliable analytical results of major component (e.g., more than 90 mass%). Purity of metal has been decided with difference method based on the quantification of trace impurities. For example, pure-iron certified reference materials have the following certified values of impurities: C, Mn, P, S, Si, Cu, Ni, Cr, N, Al, Co, Mo, O, Sn, Ti, V, W, Ag, As, B, Bi, Ca, Mg, Pb, Sb, Se, Ta, Te, Zn, and Zr. When researchers would like to be carried out the purity examination of iron-base alloy, all such elements must be quantified.
Ex. Analytical results of trace elements in JSS 001-8 pure iron of
certified reference material.
| Analytical value 1 | Analytical value 2 | Certified value | Analytical method | |
| Carbon | 0.00010 | 0.00011 | 0.00014 | Infrared absorption spectrometry after combustion |
| Silicon | <0.00002 | <0.00002 | (<0.0002) | Spectrophotometry after silicon tetrafluoride separation |
| Manganese | 0.000001 | 0.000002 | (<0.00003) | Inductively coupled plasma atomic emission spectrometry (ICP-AES) after 4-methyl-2-pentanone extraction |
| Phosphorous | <0.00001 | <0.00001 | (<0.0001) | Spectrophotometry after phosphomolybdate extraction |
| Nitrogen | 0.00012 | 0.00013 | (0.0002) | Thermal conductimetry after fusion in a current of inertgas |
| Arsenic | <0.00002 | <0.00002 | <0.00005 | ICP-AES after co-precipitation with manganese dioxide |
| Boron | 0.000010 | 0.000011 | 0.000012 | Curcumin spectrophotometry after methyl borate distillation |
| Selenium | <0.00001 | <0.00001 | <0.00005 | Graphite furnace atomic absorption spectrometry after co-precipitation with palladium |
| Niobium | <0.000008 | <0.000008 | <0.00005 | Inductively coupled plasma mass spectrometry (ICP-MS) after anion-exchange separation |
| Lead | 0.000019 | 0.000020 | 0.000019 | ICP-MS after 4-methyl-2-pentanone extraction |
3. Thin-film sample
Vapor-deposited material on a substrate has been analyzed by dissolving the
material. Amount of each elements except for gaseous analytes (H, C, N, O, and
S) and impurities in the substrate can be quantified.
4.
Released metals in a liquid sample (e.g., "Testing method for metal release from metallic biomaterials (JIS T 0304)") have been quantified. The following values can be determined: (1) concentration values in a sample solution (unit: ng/mL or μg/mL), or (2) total amount in a sample solution (unit: μg or mg).
Anion in a liquid sample solution can be quantified by ion chromatography.
Usually, these typical requests have been achieved to combine conventional analytical techniques. Cooperative study might be conducted to obtain new analytical data, which cannot be determined by using conventional methods. Please contact us if you have any analytical difficulties.