BS ISO 20424:2019 pdf download – Fatty acid methyl esters (FAME) — Determination of sulfur content — Inductively coupled plasma optical emission spectrometry (ICP-OES) method This document specifies a test method for inductively coupled plasma optical emission spectrometry(ICP-OES) for the detection of the sulfur content from 2 mg/kg to 21 mg/kg in fatty acid methylesters (FAME). NOTE 1 For the purposes of this document, the term “% (m/m)” is used to represent the mass fraction (1) ofthe material. NOTE2 The method can also be used for the determination of concentrations outside the given limits. Theprecision statement, however, is only valid for the concentration range given in the scope. NOTE3 The method described in the document was tested with FAME derived from soybean oil and beeftallow.FAME derived from other feedstock, in particular aged oils, may behave different due to the differentnature of sulfur compounds. 2Normative references The following documents are referred to in the text in such a way that some or all of their contentconstitutes requirements of this document. For dated references, only the edition cited applies.Forundated references, the latest edition of the referenced document (including any amendments) applies.ISo 3170, Petroleum liquids —Manual sampling ISO 3171, Petroleum liquids — Automatic pipeline sampling ISO 12185,Crude petroleum and petroleum products — Determination of density — OscillatingU-tube method 3Terms and definitions No terms and definitions are listed in this document. ISO and IEC maintain terminological databases for use in standardization at the following addresses: —ISO online browsing platform: available at https://www.iso.org/obp —IEC Electropedia: available at http://www.electropedia.org/ 4Principle An exactly weighed test portion is diluted with kerosene to allow the proper introduction of the aerosolinto the plasma.The resulting solution is directly injected into the plasma of the ICP-OES spectrometer. 7 sampling Samples shall be taken as described in ISo 3170 or lSO 3171. 8Preparation of stock solution and calibration solution8.1Stock solution Sulfur solution with a concentration of 50 mg/kg:add to an appropriate conical flask(6.4) approximately3,0 g of the standard sulfur solution (5.3), fill up to 30 g with diluent(5.1). Weigh the masses with an accuracy of 0,000 1 g and homogenize the solution.Calculate the exactconcentration of this solution, which shall be used to prepare the calibration solutions. lt is also permitted to prepare the dilution on volumetric basis. In this case, use appropriate pipettes(6.5) to transfer the volumes.In this case the concentration is expressed as mass/volume. Other concentrations and quantities can be used for...
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