# Fertilisers (Sampling and Analysis) Regulations (Northern Ireland) 1996, Paragraph 8: EXPRESSION OF RESULTS


See Method 25d (8).
The percentage of cobalt in the fertiliser is given by:
Co%=[(xs-xb)×V×D]/(M×104) If Method 25c is used:
Co%=[(xs-xb)×V×2D]/(M×104) where:
Co is the quantity of cobalt expressed as a percentage of the fertiliser;
xs is the concentration in μg/ml of the Co in the test solution (6.2);
xb is the concentration in μg/ml of the Co in the blank solution (7.1);
V is the volume in ml of extract obtained in accordance with Method 25a or 25b;
D is the factor corresponding to the dilution carried out in 6.2;
M is the mass in grams of the test sample taken in accordance with Method 25a or 25b.
Calculation of the dilution factor D: if (a1), (a2), (a3), . . . , (ai) and (a) are aliquot portions and (v1), (v2), (v3), . . . , (vi) and (100) are the volumes in ml corresponding to their respective dilutions, the dilution factor D is given by:
D=(v1/a1)×(v2/a2)×(v3/a3)x . . . x (vi/ai)×(100/a).

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Source: https://www.legislation.gov.uk/nisr/1996/513/schedule/2/part/I/chapter/25f./paragraph/8 (the official version)
Page: https://openlegislation.uk/fertilisers-sampling-and-analysis-regulations-northern-ireland-1996/schedule-2/part-I/chapter-25f./paragraph-8
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.