ISO INTERNATIONAL STANDARD 8892 First edition 1987-06-01 INTERNATIONALORGANIZATIONFORSTANDARDIZATION ORGANISATION INTERNATIONALEDE NORMALISATION MEKAYHAPOAHAAOPrAHW3ALMAOCTAHAAPTW3ALWM Oilseed residues - Determination of total residual hexane Tourteaux de graines oleagineuses-Dosage deI'hexane residuaire total Referencenumber ISO 8892:1987 (E) Copvriaht International Oraanization for Standardization Foreword ISo (the International Organization for Standardization) is a worldwide federation of national standards bodies (isoO member bodies). The work of preparing International Standards is normally carried out through iSO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, govern- mental and non-governmental, in liaison with iso, also take part in the work. Draft International Standards adopted by the technical committees are circulated to the member bodies for approval before their acceptance as International Standards by the ISO Council. They are approved in accordance with ISO procedures requiring at least 75 % approval by the member bodies voting. International Standard ISO8892was preparedbyTechnical Committee ISO/TC 34, Agricuitural foodproducts. Users should note that all nternational Standards undergo revision from time to time latestedition,unlessotherwisestated. )International Organization for Standardization,1987 Printed in Switzerland INTERNATIONALSTANDARD ISO8892:1987(E) Oilseed residues - Determination of total residual hexane 1 Scope and field of application with methylpolysiloxanes 1) (flm thickness 0,2 um) or, failing this, a packed column at least 1,7 m long and 2 to 4 mm inter- This International Standard specifies a method for the deter- nal diameter, packed with acid-washed diatomaceous earth of mination of thetotal amount of volatile hydrocarbons,referred particle size 150 to 180 μm2), and coated with methylpolysilox- to generally ashexane,remaining in oilseed residues after anes 1), extractionwithhydrocarbon-based solvents. If a capillary column is used, the apparatus shallhave a 1/100 input divider. Reference 5.2 Electric oven, capable of being maintained at 110 oC. Iso 5500,Oilseed residues -Sampling. 5.3 Gas syringe, graduated, of capacity 1 ml, preferably 3Principle with a valve. Desorption of hexane by heating at 110 C with water in a 5.4 Penicillin-type flasks, of capacity 50 to 60 ml, all with closed vessel, and determination of the hexane in the the same volume to within 2 %. headspace by gas chromatographyusing capillary orpacked columns. Expression of the results as n-hexane. 5.5 Septa, inert to solvents, of approximately 3mm thickness, of a material such as nitrile rubber (for example Perbunan), or butyl rubber with a PTFE or polychloroprene 4 Reagents and materials seam (for example Neoprene). 4.1 Technical n-hexane or light petroleum, with a com- NOTE -- Ensure that the septa used will produce a hermetic seal after position similar to that used in the industrial extraction of crimping. oilseeds,orfailingthat,n-hexane. 5.6Metallic foil caps, for example of aluminium. 4.2 Carrier gas : hydrogen or nitrogen, helium, etc., dry and containing less than i0 mg/kg of oxygen. 5.7 Crimping pliers. 4.3 Auxiliary gases : 5.8 Liquid syringe, of capacity 10 μl. Hydrogen, 99,9 % pure, containing no organic im- purities. 6 Samplingand sample storage Air, containing no organic impurities. See ISo 5500. It is essential that loss of hexane from the sam- ple be prevented. 5 Apparatus The laboratory sample shall fill a completely sealed container (preferablyacrimpedmetal box)and shall be stored at-20 °C Usual laboratory apparatus and in particular or below(for example in adeep-freezer).Plastics containers shall not be used. 5.1 Gas chromatograph,with flame ionization detector and The determination of residual hexane shall be carried out as integrator and/or recorder, equipp