{"id":24713,"date":"2025-11-03T15:11:52","date_gmt":"2025-11-03T08:11:52","guid":{"rendered":"https:\/\/nhathuocngocanh.com\/bp\/?p=24713"},"modified":"2025-11-03T15:11:52","modified_gmt":"2025-11-03T08:11:52","slug":"methane-intermix-2-per-cent-in-nitrogen","status":"publish","type":"post","link":"https:\/\/nhathuocngocanh.com\/bp\/methane-intermix-2-per-cent-in-nitrogen\/","title":{"rendered":"Methane Intermix (2 per cent) in Nitrogen"},"content":{"rendered":"

Edition: BP 2025 (Ph. Eur. 11.6 update)<\/p>\n

DEFINITION<\/h2>\n
A mixture containing 2 per cent V\/V of Methane (2413) in Low-oxygen nitrogen (1685).<\/p>\n
Content<\/strong><\/p>\n
1.9 per cent V\/V to 2.1 per cent V\/V of methane (CH_{4<\/sub>) in nitrogen (N_{2<\/sub>).<\/p>\n}}
This monograph applies to methane intermix (2 per cent) in nitrogen used in the preparation of lung function test gas mixtures for medicinal use.<\/p>\n

CHARACTERS<\/h2>\n
Appearance<\/strong><\/p>\n
Colourless gas.<\/p>\n
IDENTIFICATION<\/h2>\n
A. It complies with the limits of the assay.<\/p>\n
B. Gas chromatography (2.2.28).<\/p>\n
Gas to be examined The substance to be examined.<\/p>\n
Reference gas Nitrogen R1.<\/p>\n
Column:<\/p>\n
\u2014 material: stainless steel;<\/p>\n
\u2014 size: l = 2 m, \u00d8 = 2 mm;<\/p>\n
\u2014 stationary phase: molecular sieve for chromatography R (0.5 nm).<\/p>\n
Carrier gas helium for chromatography R.<\/p>\n
Flow rate 20 mL\/min.<\/p>\n
Temperature:<\/p>\n
\u2014 column: 80 \u00b0C;<\/p>\n
\u2014 detector: 130 \u00b0C.<\/p>\n
Detection Thermal conductivity.<\/p>\n
Injection 10 \u03bcL.<\/p>\n
Retention time Nitrogen = about 2 min.<\/p>\n
Results The principal peak in the chromatogram obtained with the gas to be examined is similar in retention time to the principal peak in the chromatogram obtained with the reference gas.<\/p>\n
TESTS<\/h2>\n
Water (2.5.28)<\/p>\n
Maximum 10 ppm V\/V.<\/p>\n
ASSAY<\/h2>\n
Gas chromatography (2.2.28).<\/p>\n
Gas to be examined The substance to be examined.<\/p>\n
Reference gas Mixture containing 2.0 per cent V\/V of methane R1 in nitrogen R1.<\/p>\n
Column:<\/p>\n
\u2014 material: stainless steel;<\/p>\n
\u2014 size: l = 2 m, \u00d8 = 2 mm;<\/p>\n
\u2014 stationary phase: 3 per cent squalane R on alumina.<\/p>\n
Carrier gas helium for chromatography R.<\/p>\n
Flow rate 20 mL\/min.<\/p>\n
Temperature:<\/p>\n
\u2014 column: 100 \u00b0C;<\/p>\n
\u2014 detector: 250 \u00b0C.<\/p>\n
Detection Flame ionisation.<\/p>\n
Injection 100 \u03bcL.<\/p>\n
Retention time Methane = about 0.5 min.<\/p>\n
Calculate the percentage content of CH_{4<\/sub>.<\/p>\n}
STORAGE<\/h2>\n
As a compressed gas, in appropriate high-pressure cylinders complying with the legal regulations.<\/p>\n
LABELLING<\/h2>\n
The label states the nominal content, in per cent V\/V, of methane in nitrogen.<\/p>\n
IMPURITIES<\/h2>\n
Specified impurities A.<\/p>\n
$\"Methane$ <\/p>\n
A. water.<\/p>\n","protected":false},"excerpt":{"rendered":"
Edition: BP 2025 (Ph. Eur. 11.6 update) DEFINITION A mixture containing 2 per cent V\/V of Methane (2413) in Low-oxygen nitrogen (1685). Content 1.9 per cent V\/V to 2.1 per cent V\/V of methane (CH4) in nitrogen (N2). This monograph applies to methane intermix (2 per cent) in nitrogen used in the preparation of lung…<\/p>\n","protected":false},"author":5,"featured_media":24714,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[174],"tags":[],"class_list":["post-24713","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-medicinal-substances"],"acf":[],"_links":{"self":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/24713","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/comments?post=24713"}],"version-history":[{"count":2,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/24713\/revisions"}],"predecessor-version":[{"id":24718,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/24713\/revisions\/24718"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media\/24714"}],"wp:attachment":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media?parent=24713"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/categories?post=24713"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/tags?post=24713"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}

TESTS<\/h2>\nWater (2.5.28)<\/p>\nMaximum 10 ppm V\/V.<\/p>\n

STORAGE<\/h2>\nAs a compressed gas, in appropriate high-pressure cylinders complying with the legal regulations.<\/p>\n

LABELLING<\/h2>\nThe label states the nominal content, in per cent V\/V, of methane in nitrogen.<\/p>\n

TESTS<\/h2>\n
Water (2.5.28)<\/p>\n
Maximum 10 ppm V\/V.<\/p>\n

STORAGE<\/h2>\n
As a compressed gas, in appropriate high-pressure cylinders complying with the legal regulations.<\/p>\n

LABELLING<\/h2>\n
The label states the nominal content, in per cent V\/V, of methane in nitrogen.<\/p>\n