{"id":23641,"date":"2025-11-01T08:21:26","date_gmt":"2025-11-01T01:21:26","guid":{"rendered":"https:\/\/nhathuocngocanh.com\/bp\/?p=23641"},"modified":"2025-11-10T22:35:38","modified_gmt":"2025-11-10T15:35:38","slug":"malathion","status":"publish","type":"post","link":"https:\/\/nhathuocngocanh.com\/bp\/malathion\/","title":{"rendered":"Malathion"},"content":{"rendered":"

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

(Ph. Eur. monograph 1343)<\/p>\n

\"Malathion\"<\/p>\n

C10<\/sub>H19<\/sub>O6<\/sub>PS2<\/sub> 330.4 121-75-5<\/p>\n

Action and use<\/strong><\/p>\n

Organophosphorus insecticide.<\/p>\n

Preparations<\/strong><\/p>\n

Malathion Lotion<\/p>\n

Malathion Shampoo<\/p>\n

Ph Eur<\/p>\n

DEFINITION<\/h2>\n

Diethyl (2RS)-2-(dimethoxyphosphinodithioyl)butanedioate.<\/p>\n

Content<\/strong><\/p>\n

98.0 per cent to 102.0 per cent (anhydrous substance).<\/p>\n

CHARACTERS<\/h2>\n

Appearance<\/h3>\n

Clear, colourless or slightly yellowish liquid.<\/p>\n

Solubility<\/h3>\n

Slightly soluble in water, miscible with acetone, with cyclohexane, with ethanol (96 per cent) and with vegetable oils.<\/p>\n

It solidifies at about 3 \u00b0C.<\/p>\n

IDENTIFICATION<\/h2>\n

Infrared absorption spectrophotometry (2.2.24).<\/p>\n

Comparison malathion CRS.<\/p>\n

TESTS<\/h2>\n

Relative density (2.2.5)<\/h3>\n

1.220 to 1.240.<\/p>\n

Optical rotation (2.2.7)<\/h3>\n

-0.1\u00b0 to + 0.1\u00b0.<\/p>\n

Dissolve 2.50 g in ethanol (96 per cent) R and dilute to 25.0 mL with the same solvent.<\/p>\n

Related substances<\/h3>\n

Liquid chromatography (2.2.29).<\/p>\n

Solvent mixture water R, acetonitrile R (1:3 V\/V).<\/p>\n

Test solution (a) Dissolve 0.10 g of the substance to be examined in the solvent mixture and dilute to 5.0 mL with the solvent mixture.<\/p>\n

Test solution (b) Dilute 1.0 mL of test solution (a) to 10.0 mL with the solvent mixture.<\/p>\n

Reference solution (a) Dissolve 0.100 g of malathion CRS in the solvent mixture and dilute to 50.0 mL with the solvent mixture.<\/p>\n

Reference solution (b) Dilute 0.5 mL of test solution (a) to 100.0 mL with the solvent mixture.<\/p>\n

Reference solution (c) Dissolve 5.0 mg of malathion impurity A CRS and 5.0 mg of malathion impurity B CRS in the solvent mixture, then dilute 50.0 mL with the solvent mixture.<\/p>\n

Reference solution (d) Dilute 2.0 mL of reference solution (c) to 10.0 mL with the solvent mixture.<\/p>\n

Column:<\/p>\n

\u2014 size: l = 0.15 m, \u00d8 = 4.6 mm;<\/p>\n

\u2014 stationary phase: octadecylsilyl silica gel for chromatography R (10 \u03bcm);<\/p>\n

\u2014 temperature: 35 \u00b0C.<\/p>\n

Mobile phase acetonitrile R, water R (45:55 V\/V).<\/p>\n

Flow rate 1 mL\/min.<\/p>\n

Detection Spectrophotometer at 210 nm.<\/p>\n

Injection 20 \u03bcL of test solution (a) and reference solutions (b), (c) and (d).<\/p>\n

Retention time Impurity B = about 3.5 min; impurity A = about 5 min; malathion = about 16 min.<\/p>\n

System suitability Reference solution (c):<\/p>\n

\u2014 resolution: minimum 2.0 between the peaks due to impurities B and A.<\/p>\n

Limits:<\/p>\n

\u2014 impurity A: not more than 3 times the area of the corresponding peak in the chromatogram obtained with reference solution (d) (0.3 per cent);<\/p>\n

\u2014 impurity B: not more than the area of the corresponding peak in the chromatogram obtained with reference solution (d) (0.1 per cent);<\/p>\n

\u2014 sum of impurities other than A and B: not more than twice the area of the principal peak in the chromatogram obtained with reference solution (b) (1 per cent);<\/p>\n

\u2014 disregard limit: 0.1 times the area of the principal peak in the chromatogram obtained with reference solution (b) (0.05 per cent).<\/p>\n

Water (2.5.12)<\/h3>\n

Maximum 0.1 per cent, determined on 2.000 g.<\/p>\n

ASSAY<\/h2>\n

Liquid chromatography (2.2.29) as described in the test for related substances with the following modifications.<\/p>\n

Injection Test solution (b) and reference solution (a).<\/p>\n

System suitability Reference solution (a):<\/p>\n

\u2014 repeatability: maximum relative standard deviation of 1.0 per cent after 6 injections.<\/p>\n

Calculate the percentage content of C10<\/sub>H19<\/sub>O6<\/sub>PS2 <\/sub>from the declared content of malathion CRS.<\/p>\n

STORAGE<\/h2>\n

In an airtight container, protected from light.<\/p>\n

IMPURITIES<\/h2>\n

Specified impurities A, B.<\/p>\n

Other detectable impurities (the following substances would, if present at a sufficient level, be detected by one or other of the tests in the monograph. They are limited by the general acceptance criterion for other\/unspecified impurities and\/or by the general monograph Substances for pharmaceutical use (2034). It is therefore not necessary to identify these impurities for demonstration of compliance. See also 5.10.<\/p>\n

Control of impurities in substances for pharmaceutical use) C.<\/p>\n

\"Malathion\"<\/p>\n

A. diethyl (2RS)-2-[(methoxy)(methylsulfanyl)-S-phosphinothioyl]butanedioate (isomalathion),<\/p>\n

\"Malathion\"<\/p>\n

B. diethyl (2RS)-2-(dimethoxy-S-phosphinothioyl)butanedioate (maloxon),<\/p>\n

\"Malathion\"<\/p>\n

C. ethyl and methyl (2RS)-2-(dimethoxyphosphinodithioyl)butanedioate (methyl analogue).
\nPh Eur<\/p>\n","protected":false},"excerpt":{"rendered":"

Edition: BP 2025 (Ph. Eur. 11.6 update) (Ph. Eur. monograph 1343) C10H19O6PS2 330.4 121-75-5 Action and use Organophosphorus insecticide. Preparations Malathion Lotion Malathion Shampoo Ph Eur DEFINITION Diethyl (2RS)-2-(dimethoxyphosphinodithioyl)butanedioate. Content 98.0 per cent to 102.0 per cent (anhydrous substance). CHARACTERS Appearance Clear, colourless or slightly yellowish liquid. Solubility Slightly soluble in water, miscible with acetone,…<\/p>\n","protected":false},"author":5,"featured_media":23642,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[174],"tags":[],"class_list":["post-23641","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\/23641","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=23641"}],"version-history":[{"count":5,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/23641\/revisions"}],"predecessor-version":[{"id":29694,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/23641\/revisions\/29694"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media\/23642"}],"wp:attachment":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media?parent=23641"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/categories?post=23641"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/tags?post=23641"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}