ISO 10565 pdf download

ISO 10565 pdf download.Oilseeds — Simultaneous determination of oil and water contents — Method using pulsed nuclear magnetic resonance spectrometry 1 Scope This International Standard specifies a rapid method for the determination of the oil and water contents of commercial oilseeds using pulsed nuclear magnetic resonance (NMR). It is applicable to rapeseeds, soya beans, linseeds and sunflower seeds with a water content less than 1 0 %. For seeds with higher water contents, drying is necessary before the oil content can be determined by pulsed NMR. NOTE 1 This method has been tested with rapeseeds, soya beans, linseeds and sunflower seeds. This does not, however, preclude its applicability to other commercial seeds whose oil is liquid at the temperature of measurement. NOTE 2 The reproducibility values are generally higher than those obtained by the drying method (ISO 665). 2 Normative references The following standards contain provisions which through reference in this text, constitute provisions of this International Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO 659:1 988, Oilseeds — Determination of hexane extract (or light petroleum extract), called “oil content”. ISO 664:1 990, Oilseeds — Reduction of laboratory sample to test sample. ISO 665:1 977, Oilseeds — Determination of moisture and volatile matter content. 3 Principle Insertion of the test sample into the magnetic field of a pulsed NMR spectrometer. Application of an alternating electromagnetic field in the form of an intense 90° radiofrequency (RF) pulse which excites all the hydrogen nuclei. Recording of the free induction decay (FID) following the 90° pulse. The maximum amplitude of this signal is proportional to the total number of protons from the water and oil phases of the sample.Application of the second RF pulse, a so-called 1 80° pulse, to produce a spin-echo signal when only the signal from the oil phase contributes to the FID. NOTE 1 The maximum amplitude of this echo signal is proportional to the oil content. It varies with the sample temperature following a complex law. An increase in temperature decreases the measured value of the echo. Calculation of the difference between the two amplitudes, which is proportional to the...