Svensk läkemedelsstandard

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1 Svensk läkemedelsstandard Nitrogen Postadress/Postal address: P.O. Box 26, SE Uppsala, SWEDEN Besöksadress/Visiting address: Dag Hammarskjölds väg 42, Uppsala Telefon/Phone: +46 (0) Fax: +46 (0) Internet:

2 Ansvarig utgivare: Svenska farmakopékommittén Läkemedelsverket Box 26 S Uppsala, Sweden Tel. 018/ (5)

3 NITROGEN 1 Nitrogenium N 2 M r [ ] DEFINITION Content: minimum 99.5 per cent V/V of N 2. This monograph applies to nitrogen for medicinal use. CHARACTERS Appearance: colourless, odourless gas. Solubility: at 20 C and at a pressure of 101 kpa, 1 volume dissolves in about 62 volumes of water and about 10 volumes of ethanol (96 per cent). PRODUCTION Carbon dioxide: maximum 300 ppm V/V, determined using an infrared analyser (2.5.24). Gas to be examined. The substance to be examined. It must be filtered to avoid stray light phenomena. Reference gas (a). Nitrogen R1. Reference gas (b). Mixture containing 300 ppm V/V of carbon dioxide R1 in nitrogen R1. Calibrate the apparatus and set the sensitivity using reference gases (a) and (b). Measure the content of carbon dioxide in the gas to be examined. Carbon monoxide: maximum 5 ppm V/V, determined using an infrared analyser (2.5.25). Gas to be examined. The substance to be examined. It must be filtered to avoid stray light phenomena. Reference gas (a). Nitrogen R1. Reference gas (b). Mixture containing 5 ppm V/V of carbon monoxide R in nitrogen R1. Calibrate the apparatus and set the sensitivity using reference gases (a) and (b). Measure the content of carbon monoxide in the gas to be examined. Oxygen: maximum 50 ppm V/V, determined using an oxygen analyser with a detector scale ranging from ppm V/V and equipped with an electrochemical cell. The gas to be examined passes through a detection cell containing an aqueous solution of an electrolyte, generally potassium hydroxide. The presence of oxygen in the gas to be examined produces variation in the electric signal recorded at the outlet of the cell that is proportional to the oxygen content. 1 Kapitlet är hämtat från Ph Eur 9th Ed för information. I händelse av tvist gäller alltid det vid tillfället giltiga kapitlet i Ph Eur. 3(5)

4 Calibrate the analyser according to the instructions of the manufacturer. Pass the gas to be examined through the analyser using a suitable pressure regulator and airtight metal tubes and operating at the prescribed flow-rates until constant readings are obtained. Water (2.5.28): maximum 67 ppm V/V. Assay. Gas chromatography (2.2.28). Gas to be examined. The substance to be examined. Reference gas (a). Ambient air. Reference gas (b). Nitrogen R1. Column: material: stainless steel; size: l = 2 m, Ø = 2 mm; stationary phase: molecular sieve for chromatography R (0.5 nm). Carrier gas: helium for chromatography R. Flow rate: 40 ml/min. Temperature: column: 50 C; detection: 130 C. Detection: thermal conductivity. Injection: loop injector. Inject reference gas (a). Adjust the injected volumes and operating conditions so that the height of the peak due to nitrogen in the chromatogram obtained with the reference gas is at least 35 per cent of the full scale of the recorder. System suitability: the chromatograms obtained show a clear separation of oxygen and nitrogen. Calculate the content of N 2 in the gas to be examined. IDENTIFICATION First identification: A. Second identification: B, C. A. Examine the chromatograms obtained in the assay (see Production). Results: the principal peak in the chromatogram obtained with the substance to be examined is similar in retention time to the principal peak in the chromatogram obtained with reference gas (b). B. In a 250 ml conical flask replace the air by the substance to be examined. Place a burning or glowing splinter of wood in the flask. The splinter is extinguished. C. In a suitable test tube, place 0.1 g of magnesium R in turnings. Close the tube with a two-hole stopper fitted with a glass tube reaching about 1 cm above the turnings. Pass the substance to be examined through the glass tube for 1 min without heating, then for 15 min while heating the test tube to a red glow. After cooling, add 5 ml of dilute sodium hydroxide solution R. The evolving vapours change the colour of moistened red litmus paper R blue. 4(5)

5 TESTS Carbon dioxide (2.1.6): maximum 300 ppm V/V, determined using a carbon dioxide detector tube. Carbon monoxide (2.1.6): maximum 5 ppm V/V, determined using a carbon monoxide detector tube. Water vapour (2.1.6): maximum 67 ppm V/V, determined using a water vapour detector tube. STORAGE As a compressed gas or a liquid in appropriate containers complying with the legal regulations. IMPURITIES Specified impurities: A, B, C, D. A. CO 2 : carbon dioxide, B. CO: carbon monoxide, C. O 2 : oxygen, D. H 2 O: water. 5(5)

Svensk läkemedelsstandard

Svensk läkemedelsstandard 2017.2 Nitrous oxide Postadress/Postal address: P.O. Box 26, SE-751 03 Uppsala, SWEDEN Besöksadress/Visiting address: Dag Hammarskjölds väg 42, Uppsala Telefon/Phone: +46 (0)18