{
  "url": "https://openlegislation.uk/fertilisers-sampling-and-analysis-regulations-northern-ireland-1996/schedule-2/part-I/chapter-25e./paragraph-4",
  "json_url": "https://openlegislation.uk/fertilisers-sampling-and-analysis-regulations-northern-ireland-1996/schedule-2/part-I/chapter-25e./paragraph-4.json",
  "legislation": "nisr/1996/513",
  "legislation_title": "Fertilisers (Sampling and Analysis) Regulations (Northern Ireland) 1996",
  "legislation_url": "https://openlegislation.uk/fertilisers-sampling-and-analysis-regulations-northern-ireland-1996",
  "path": "schedule/2/part/I/chapter/25e./paragraph/4",
  "kind": "paragraph",
  "number": "4",
  "heading": "REAGENTS",
  "text": "EDTA buffer solution\n4.1 Place in a 500 ml volumetric flask containing 300 ml of water:\n— 75 g of ammonium acetate (NH4OOCCH3);\n— 10 g of disodium salt of ethylene diamine tetraacetic acid (Na2EDTA);\n— 40 ml of acetic acid (CH3COOH, ρ = 1.05 g/ml).\nMake up to volume with water and mix thoroughly. The pH of the solution, checked by means of a glass electrode, must be 4.8 ± 0.1.\nAzomethine-H solution\n4.2 Place in a 200 ml volumetric flask\n— 10 ml of the buffer solution (4.1);\n— 400 mg of azomethine-H (C17H12NNaO8S2);\n— 2 g of ascorbic acid (C6H8O6).\nMake up to volume and mix thoroughly. Do not prepare large quantities of this reagent as it is stable for only a few days.\nBoron calibration solutions\n4.3 Boron stock solution (100 μg/ml)\n4.3.1 Dissolve 0.5719 g of boric acid (H3BO3) in water in a 1000 ml volumnetric flask. Make up to volume with water and mix thoroughly. Transfer to a plastic bottle for storage in a refrigerator.\nBoron working solution (10 μg/ml)\n4.3.2 Place 50 ml of stock solution (4.3.1) in a 500 ml volumetric flask. Make up to volume with water and mix thoroughly.",
  "extent": null,
  "status": null,
  "version": "current",
  "annotations": [],
  "outstanding_effects": [],
  "provenance": {
    "source": "legislation.gov.uk",
    "source_url": "https://www.legislation.gov.uk/nisr/1996/513/schedule/2/part/I/chapter/25e./paragraph/4",
    "retrieved_at": "2026-10-29T02:32:40.012993+00:00"
  },
  "licence": "Open Government Licence v3.0",
  "licence_url": "https://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/",
  "attribution": "Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives."
}