# Fertilisers (Sampling and Analysis) Regulations (Northern Ireland) 1996, Paragraph 4: REAGENTS


Hydrochloric acid solution, about 6M
4.1 See Method 25d (4.1).
Hydrochloric acid solution, about 0.5 M
4.2 See Method 25d (4.2).
Lanthanum salt solutions (10 g of La per litre)
4.3 See Method 25d (4.3).
Cobalt calibration solutions
4.4 Cobalt stock solution (1000 μg/ml)
4.4.1 In a 250 ml beaker, weigh to the nearest 0.1 mg, 1 g of cobalt, add 25 ml of 6 M hydrochloric acid (4.1) and heat on a hot plate until the cobalt is completely dissolved. When cool, transfer quantitatively to a 1000 ml volumetric flask. Make up to volume with water and mix thoroughly.
Cobalt working solution (100 μg/ml)
4.4.2 Place 10 ml of the stock solution (4.4.1) in a 100 ml volumetric flask. Make up to volume with 0.5 M hydrochloric acid solution (4.2) and mix thoroughly.

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Source: https://www.legislation.gov.uk/nisr/1996/513/schedule/2/part/I/chapter/25f./paragraph/4 (the official version)
Page: https://openlegislation.uk/fertilisers-sampling-and-analysis-regulations-northern-ireland-1996/schedule-2/part-I/chapter-25f./paragraph-4
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.