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


See Method 25d (8).
The percentage of zinc in the fertiliser is:
Zn%=[(xs-xb)×V×D]/(M×104) If Method 25c has been used:
Zn%=[(xs-xb)×V×2D]/(M×104) where:
Zn is the quantity of zinc expressed as a percentage of the fertiliser;
xs is the mass in μg of Zn in the test solution (6.2);
xb is the mass in μg of Zn in the blank solution (7.1);
V is the volume in ml of the extract solution obtained in accordance with Method 25a or 25b;
D is the factor corresponding to the dilution performed in 6.2;
M is the mass in g of the test sample taken in accordance with Method 25a or 25b.
Calculation of the dilution factor D: where (a1), (a2), (a3), . . . , (ai) and (a) are successive aliquot portions and (v1), (v2), (v3), . . . , (vi) and (100) are volumes corresponding to their respective dilutions, the dilution factor D will be:
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/25k./paragraph/8 (the official version)
Page: https://openlegislation.uk/fertilisers-sampling-and-analysis-regulations-northern-ireland-1996/schedule-2/part-I/chapter-25k./paragraph-8
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.