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


3.1 Sodium hydroxide solution: 40 g per 100 ml, ammonia free.
3.2 Sulfuric acid, 0.05 M solution.
3.3 Sulfuric acid, 0.1 M solution.
3.4 Sulfuric acid, 0.25 M solution.
3.5 Sodium hydroxide, 0.2 M solution, carbonate free.
3.6 Chromium metal powder, 100 mesh, low nitrogen content.
3.7 Anti-bump granules of pumice stone, washed in hydrochloric acid and ignited.
3.8 Anti-foaming agent, paraffin wax.
3.9 sulfuric acid (ρ = 1.84 g/ml).
3.10 Hydrochloric acid (ρ = 1.18 g/ml).
3.11 Catalyst mixture: 1000 g potassium sulfate and 50 g copper sulfate pentahydrate. The ingredients must be ground and thoroughly mixed.
Indicator solutions
3.12 Mixed indicator:
3.12.1 Mix 50 ml of 2 g/litre ethanolic solution of methyl red with 50 ml of 1 g/litre ethanolic solution of methylene blue.
Methyl red indicator:
3.12.2 Dissolve 0.1 g methyl red in 50 ml ethanol. This indicator may be used instead of the preceding one.
3.13 pH indicator paper, wide range.

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