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


Dilute hydrochloric acid (HCl) solution, about 6 M:
4.1 Mix one volume of hydrochloric acid (ρ = 1.18 g/ml) with 1 volume of water.
Dilute hydrochloric acid (HCl) solution, about 0.5 M:
4.2 Mix one volume of hydrochloric acid (ρ = 1.18 g/ml) with 20 volumes of water.
4.3 Lanthanum salt solutions (10 g of La per litre).
This reagent is used for determinations of cobalt, iron, manganese and zinc. Lanthanum is added to the extract to eliminate chemical interferences in the air-acetylene flame. It can be prepared either:
(a) with lanthanum oxide dissolved in hydrochloric acid (4.1). Place 11.73 g of lanthanum oxide (La2O3) in 150 ml water in a 1 litre volumetric flask and add 120 ml of 6 M hydrochloric acid (4.1). Allow to dissolve and then make up to 1 litre with water and mix thoroughly. This solution is approximately 0.5 M in hydrochloric acid; or
(b) with solutions of lanthanum chloride, sulfate or nitrate. Place 26.7 g of lanthanum chloride heptahydrate (LaCl3.7H2O) or 31.2 g of lanthanum nitrate hexahydrate [La(NO3)3.6H2O] or 26.2 g of lanthanum sulfate nonahydrate [La2(SO4)3.9H2O] in 150 ml of water in a 1 litre volumetric flask, then add 85 ml of 6 M hydrochloric acid (4.1). Allow to dissolve and then make up to 1 litre with water. Mix thoroughly. This solution is approximately 0.5 M in hydrochloric acid.
Calibration solutions
4.4 For the preparation of these, see the individual method of determination for each trace element.

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