Edition: BP 2025 (Ph. Eur. 11.6 update)<\/p>\n
Content<\/p>\n
99.0 per cent to 101.0 per cent of 4-hydroxy-3-methoxybenzaldehyde (dried substance).<\/p>\n
White or slightly yellowish, crystalline powder or needles.<\/p>\n
Slightly soluble in water, freely soluble in ethanol (96 per cent) and in methanol. It dissolves in dilute solutions of alkali hydroxides.<\/p>\n
First identification: B. <\/em><\/p>\n Second identification: A, C.<\/em><\/p>\n A. Melting point (2.2.14): 81 \u00b0C to 84 \u00b0C.<\/p>\n B. Infrared absorption spectrophotometry (2.2.24).<\/p>\n Comparison\u00a0 vanillin CRS.<\/p>\n C. To 5 mL of a saturated solution of the substance to be examined add 0.2 mL of ferric chloride solution R1. A blue colour is produced. Heat to 80 \u00b0C. The solution becomes brown. On cooling, a white precipitate is formed.<\/p>\n Dissolve 1.0 g in ethanol (96 per cent) R and dilute to 20 mL with the same solvent. The solution is clear (2.2.1) and not more intensely coloured than reference solution B6 (2.2.2, Method II).<\/p>\n Thin-layer chromatography (2.2.27).<\/p>\n Test solution (a)\u00a0 Dissolve 0.1 g of the substance to be examined in methanol R and dilute to 5 mL with the same solvent.<\/p>\n Test solution (b)\u00a0 Dilute 1 mL of test solution (a) to 10 mL with methanol R.<\/p>\n Reference solution (a)\u00a0 Dissolve 10 mg of vanillin CRS in methanol R and dilute to 5 mL with the same solvent.<\/p>\n Reference solution (b) Dilute 0.5 mL of test solution (a) to 100 mL with methanol R. Plate TLC silica gel F254 plate R.<\/p>\n Mobile phase anhydrous acetic acid R, methanol R, methylene chloride R (0.5:1:98.5 V\/V\/V). Application 5 \u00b5L.<\/p>\n Development\u00a0 In an unsaturated tank over 1\/2 of the plate.<\/p>\n Drying\u00a0 In a current of cold air.<\/p>\n Detection A\u00a0 Examine in ultraviolet light at 254 nm.<\/p>\n Results A Any spot in the chromatogram obtained with test solution (a), apart from the principal spot, is not more intense than the spot in the chromatogram obtained with reference solution (b) (0.5 per cent).<\/p>\n Detection B\u00a0 Spray with dinitrophenylhydrazine-aceto-hydrochloric solution R and examine in daylight.<\/p>\n Results B Any spot in the chromatogram obtained with test solution (a), apart from the principal spot, is not more intense than the spot in the chromatogram obtained with reference solution (b) (0.5 per cent).<\/p>\n Dissolve 50 mg in 5 mL of sulfuric acid R. After 5 min, the solution is not more intensely coloured than a mixture of 4.9 mL of yellow primary solution and 0.1 mL of red primary solution or a mixture of 4.9 mL of yellow primary solution and 0.1 mL of blue primary solution (2.2.2, Method I).<\/p>\n (2.2.32): maximum 1.0 per cent, determined on 1.000 g by drying in a desiccator for 4 h.<\/p>\n (2.4.14): maximum 0.05 per cent, determined on 2.0 g.<\/p>\n Dissolve 0.120 g in 20 mL of ethanol (96 per cent) R and add 60 mL of carbon dioxide-free water R. Titrate with 0.1 M sodium hydroxide, determining the end-point potentiometrically (2.2.20).<\/p>\n 1 mL of 0.1 M sodium hydroxide is equivalent to 15.21 mg of C8<\/sub>H8<\/sub>O3<\/sub>.<\/p>\n Store protected from light.<\/p>\n","protected":false},"excerpt":{"rendered":" Edition: BP 2025 (Ph. Eur. 11.6 update) DEFINITION Content 99.0 per cent to 101.0 per cent of 4-hydroxy-3-methoxybenzaldehyde (dried substance). CHARACTERS Appearance White or slightly yellowish, crystalline powder or needles. Solubility Slightly soluble in water, freely soluble in ethanol (96 per cent) and in methanol. It dissolves in dilute solutions of alkali hydroxides. IDENTIFICATION First…<\/p>\n","protected":false},"author":5,"featured_media":31018,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[174],"tags":[],"class_list":["post-31015","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\/31015","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=31015"}],"version-history":[{"count":2,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/31015\/revisions"}],"predecessor-version":[{"id":31041,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/31015\/revisions\/31041"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media\/31018"}],"wp:attachment":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media?parent=31015"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/categories?post=31015"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/tags?post=31015"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}TESTS<\/h2>\n
Appearance of solution<\/h3>\n
Related substances<\/h3>\n
Reaction with sulfuric acid<\/h3>\n
Loss on drying<\/h3>\n
Sulfated ash<\/h3>\n
ASSAY<\/h2>\n
STORAGE<\/h2>\n