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


Express the result of the analysis as the percentage of ammoniacal nitrogen in the fertiliser as received for analysis using the formula
%N=(50-A)×F for variants (a)and (b)and %N=(35-A)×F for variant (c) where
50 (or 35 where variant (c) applies) = millilitres of standard solution of sulfuric acid in the receiving flask.
A = m illilitres of sodium or potassium hydroxide used for the titration.
F = factor taking into account the weight of sample, the dilution, the volume of the aliquot portion distilled and the volumetric equivalent.
TABLE FOR METHOD 2
Determination of the ammoniacal nitrogen and of the ammoniacal and nitrate nitrogen in fertilisers. Table of the weighing, dilution and calculation to be carried out for each of the variants (a), (b) and (c) of the method.Variant (a) —Approximate maximum quantity of nitrogen to be distilled = 50 mgSulfuric acid 0.05 M to be placed in the receiving flask = 50 mlTitration with sodium or potassium hydroxide, 0.1 M solution
Declaration N%
Amount to be weighed (g)
(Volume) Dilution (ml)
Volume of sample solution to be distilled (ml)
Factor F
0-5
10
500
50
0.14
5-10
10
500
25
0.28
10-15
7
500
25
0.40
15-20
5
500
25
0.56
20-40
7
500
10
1.00
Variant (b) —Approximate maximum quantity of nitrogen to be distilled = 100 mgSulfuric acid 0.1 M to be placed in the receiving flask = 50 mlTitration with sodium or potassium hydroxide, 0.2 M solution
Declaration N%
Amount to be weighed (g)
(Volume) Dilution (ml)
Volume of sample solution to be distilled (ml)
Factor F
0-5
10
500
100
0.14
5-10
10
500
50
0.28
10-15
7
500
50
0.40
15-20
5
500
50
0.56
20-40
7
500
50
1.00
Variant (c) —Approximate maximum quantity of nitrogen to be distilled = 200 mgSulfuric acid 0.25 M to be placed in the receiving flask = 35 mlTitration with sodium or potassium hydroxide, 0.5 M solution
Declaration N%
Amount to be weighed (g)
(Volume) Dilution (ml)
Volume of sample solution to be distilled (ml)
Factor F
0-5
10
500
200
0.175
5-10
10
500
100
0.350
10-15
7
500
100
0.500
15-20
5
500
100
0.700
20-40
5
500
50
1.400

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