ISO 14939 pdf download

ISO 14939 pdf download.Animal feeding stuffs — Determination of carbadox content — Method using high-performance liquid chromatography 1 Scope This International Standard specifies a high-performance liquid chromatographic (HPLC) method for the determination of the carbadox content in premixtures and animal feeding stuffs. The method is applicable to animal feeding stuffs with a mass fraction of carbadox of 0,5 mg/kg (limit of quantification) to 1 00 mg/kg, and to premixtures with a mass fraction of carbadox up to 1 0 %. The lower limit of detection is 0,1 mg/kg. NOTE 1 For animal feeding stuffs the mass fraction of carbadox is expressed in milligrams per kilogram, and for premixtures as a percentage by mass. NOTE 2 Carbadox is a chemotherapeuticum belonging to the quinoxaline group. Carbadox is used as a growth-promoting feed additive for piglets. 2 Normative reference The following normative document contains provisions which, through reference in this text, constitute provisions of this International Standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members of IEC and ISO maintain registers of currently valid International Standards. ISO 6498:1 998, Animalfeeding stuffs — Preparation oftestsamples 3 Principle Carbadox is extracted from the sample with a mixture of acetonitrile and methanol. Animal feeds are prewetted with water. The extract of animal feeds is purified through a short aluminium oxide column. The extract of premixtures is directly diluted with a mixture of water, acetonitrile and methanol. The final extract is analysed by reverse-phase HPLC with UV detection at a wavelength of 365 nm (see references [1 ] to [3]). The presence of dimetridazole, nitrofurazone or sulfadimidine sodium can interfere with the determination of carbadox. Alternatively, carbadox may be determined after post-column derivatization with sodium hydroxide with detection at a wavelength of 420 nm. 4 Reagents Use only reagents of recognized analytical grade. 4.1 Water, demineralized or deionized, with resistivity of at least 1 0 M? ? cm, or water of at least equivalent purity. 4.2 Extraction solvent: mixture of acetonitrile and methanol (1 :1 by volume). Combine equal volumes of acetonitrile and methanol. Mix well and allow to adjust to room temperature before use. 4.3 Dilution...