ISO 21461:2012 pdf download.Rubber一Determination of the aromaticity of oil in vulcanized rubber compounds.
ISO 21461 provides a method for the selective determination of polyaromaticity of oil in vulcanized rubber compounds. The method is based on nuclear magnetic resonance (NMR) spectrometry.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 1407, Rubber — Determination of solvent extract
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
PAH
polycyclic aromatic hydrocarbon
organic compounds consisting of two or more aromatic rings where certain carbon atoms are common to two or three rings
4 Reagents and materials
All reagents shall be of recognized analytical grade unless specified in a different way.
4.1 Extraction
4.1.1 Acetone.
4.2 Sample preparation reagents
4.2.1 n-l-Ieptane, pa grade.
4.2.2 Nitrogen, purity required > 99,9 %, for protecting the extract from oxidation during the drying step.
4.2.3 Hexamethyldisiloxane (HMDS), 99,5 %, NMR grade, or tetramethylsilane (TMS), 99,5 %, NMR grade.
4.2.4 Deuterated chloroform (CDCI3), > 99,95 % deuteration degree, NMR grade containing 0,05 % TMS or
0,03 % HMDS (4.2.3). The resonance peak of either TMS or HMDS is used for the calibration of the horizontal scale of the spectrum.
4.2.5 Acetaldehyde, purity  99,5 %, may optionally be added at a concentration of 0,6 % to the deuterated chloroform containing the TMS or HMDS (4.2.4). The added acetaldehyde provides a resonance peak at around 9,8 ppm which is useful for a good phasing of the spectrum. The solution has to be prepared freshly in order to avoid interference from acetaldehyde decomposition products formed upon ageing.
5 Apparatus
Analytical balance, accurate to 0,1 mg.
5.2 Extraction apparatus, as specified in Iso 1407.
5.3 Steam bath.
5.4 Extract purification apparatus, consisting of the items specified in 5.4.1 to 5.4.4.
5.4.1 For single sample purification at one time (manually operated filtration):
a) 2 cm3, 5 cm3, 10 cm3 and 25 cm3 or 30 cm3 syringes with conical end fitting compatible with solid phase extraction (SPE) columns for manually operated purification.
b) SPE cartridge containing 500 mg or 1 000 mg of silica gel.
5.4.2 For simultaneous purification of multiple samples (optional):
a) 2 cm3, 5 cm3, 10 cm3 and 25 cm3 or 30 cm3 syringes with conical end fitting compatible with Solid Phase Extraction (SPE) columns for manually operated purification.
b) SPE cartridge containing 500 mg or 1 000 mg of silica gel.
C) Solid phase filtration equipment connected to a vacuum pump, for simultaneous purification of many samples.
d) Glass test tubes, to collect the filtrate and compatible with the filtration device4).
5.4.3 Laboratory glassware.
5.4.4 Disposable needle.
5.5 NMR spectrometer, at least 200 MHz, preferably with the following acquisition parameters.ISO 21461 pdf download.