# Fertilisers (Sampling and Analysis) Regulations (Northern Ireland) 1996, Paragraph 3: PRINCIPLE


The direct application of Kjeldahl’s method cannot be applied to calcium cyanamides containing nitrates. For this reason the nitric nitrogen is reduced to ammonia with metallic iron and stannous chloride before Kjeldahl digestion. The ammoniacal nitrogen is then determined as in Method 4a.

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Source: https://www.legislation.gov.uk/nisr/1996/513/schedule/2/part/I/chapter/4b./paragraph/3 (the official version)
Page: https://openlegislation.uk/fertilisers-sampling-and-analysis-regulations-northern-ireland-1996/schedule-2/part-I/chapter-4b./paragraph-3
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.