BS ISO 771-2021 pdf free download – Oilseed meals — Determination of moisture and volatile matter content.
This document specifies a method for the determination of the moisture and volatile matter content ofoilseed meals obtained by the extraction of oil from oilseeds by pressure and/or solvent.
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 5502,Oilseed residues — Preparation of test samples
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
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/
3.1
moisture and volatile matter content
loss in weight measured under the operating conditions specified in this document
Note 1 to entry:The moisture and volatile matter content is expressed as a mass fraction in grams per 100 g.
4Principle
The sample is ground to a particle size of 1 mm, followed by drying of a test portion at (103 ±2) °C in anoven at atmospheric pressure, until practically constant mass is reached.
5 Apparatus
5.1Analytical balance, readability 0,000 1 g, weighing precision 0,001 g.
5.2 Mechanical mill, easy to clean and allowing the meals to be ground, without heating and withoutappreciable change in the moisture, volatile matter and oil content, to particles passing completelythrough the sieve (5.3).
5.3Sieve, with apertures of diameter 1 mm.
5.4 Flat-bottomed vessel, of metal, resistant to attack under the test conditions, provided with a well-fitting lid and allowing the test portion to be spread to about 0,2 g/cm2 (e.g. diameter of vessel 50 mmto 70 mm, height about 30 mm).Glass vessels with ground closures may also be used.
8 Expression of results — Method of calculation and formula
The moisture and volatile matter content w, as a mass fraction in grams per 100 g, is given by Formula (1):
m 0 is the mass, in grams, of the vessel;
m 1 is the mass, in grams, of the vessel and test portion before drying;
m 2 is the mass, in grams, of the vessel and test portion after drying.
Use the mean value from the 2 reps if repeatability conditions are satisfied (9.2) and express the result to one decimal place.
9 Precision
9.1 Results of interlaboratory test
Details of an interlaboratory test on the precision of the method are summarized in Annex A.The valuesderived from this interlaboratory test might not be applicable to concentration ranges and matricesother than those given.
9.2Repeatability
The absolute difference between two independent single test results, obtained using the same methodon identical test material in the same laboratory by the same operator using the same equipment withina short interval of time, will in not more than 5 % of cases be greater than rgiven as followed:
– for mean value less than 4,0 % (in mass fraction): r = 0,2%;
– for mean value more than 4,0 % (in mass fraction);: r = 0,018x+0,13 (see Figure A.1).
With x corresponding to the mean value of two reps. Some examples of r values are given in Annex B.9.3 Reproducibility
The absolute difference between two single test results, obtained using the same method on identicaltest material in different laboratories with different operators using different equipment, will in notmore than 5 % of cases be greater than R given as followed:
– for mean value less than 4,0 % (in mass fraction):R = 0,4 %;
— for mean value more than 4,0 % (in mass fraction): R =0,033x +0,27(see FigureA.1).
With x corresponding to the mean value of two reps.Some examples of R values are given in Annex B.10 Test report
The test report shall specify:
a) all information necessary for the complete identification of the sample;
b) the test method used with reference to this document, i.e.ISO 771:2021;BS ISO 771 pdf download.