The Fertilisers (Sampling and Analysis) Regulations (Northern Ireland) 1991

Variant (c)

• Approximate maximum quantity of nitrogen to be distilled = 200 mg Sulphuric acid 0.5 N to be placed in the receiving flask = 35 ml Titration with sodium or potassium hydroxide, 0.5 N solution

Declaration N%	Amount to be weighed (g)	Dilution (ml)	Solution of sample to be distilled (ml)	Expression of the result (1) N% = (50−A) F
(1) For the purposes of the formula for expression of the result: 50 or 35 = millilitres of standard solution of sulphuric acid to be placed in the receiving flask; A = millilitres 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 part distilled and the volumetric equivalent.
0-5	10	500	200	(35−A) × 0.175
5-10	10	500	100	(35−A) × 0.350
l0-15	7	500	100	(35−A) × 0.500
15-20	5	500	100	(35−A) × 0.700
20-40	5	500	50	(35−A) × 1.400