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Montmorillonite-Illite (1g557)



Publication date
16 May 2012 (Last updated on: 6 June 2016)


Recommended Method

as of:

- Commission Implementing Regulation (EU) 2016/1964

For the determination in feed additive:

- X-ray diffraction (XRD) and

- inductively coupled plasma atomic emission spectroscopy (ICP-AES)

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Executive Summary

In the current application authorisation is sought under articles 4(1) and 10(2) for Bentonite-Montmorillonite as feed additive under the category/functional groups 1(g) and 1(m) "technological feed additives"/"binders" and "substances for the reduction of the contamination of feed by mycotoxins" according to the classification system of Annex I of Regulation (EC) No 1831/2003. The authorisation is sought for the use for all animal species and categories.

The active substance is Bentonite-Montmorillonite, a fine light grey powder, originated from volcanic ash in the Scandinavian region. The main clay constituents are the mineral Montmorillonite (25 - 34 mass %) and Illite (26 - 29 mass %).

The feed additive is intended to be included in premixtures or added into feedingstuffs. The Applicant suggested an inclusion level of Bentonite-Montmorillonite in complete feedingstuffs ranging from 4 to 20 g/kg.

For the determination of the mineralogical and geological parameters of Bentonite-Montmorillonite as feed additive the Applicant listed several crystallographic methods, including X-Ray Diffraction (XRD), Fourier transformed infrared spectroscopy (FTIR), and the several chemical analysis methods (i.e. Inductively coupled plasma atomic emission spectroscopy ICP-AES; Inductively coupled plasma mass spectrometry (ICP-MS)ICP-MS and Atomic absorption spectroscopy (AAS). The EURL recommends for official control the crystallographic characterisation by X‑ray diffraction (XRD) together with the elemental analysis by ICP-AES for the determination of Bentonite-Montmorillonite in the feed additive.

The Applicant is aware that the direct determination of Bentonite-Montmorillonite added to premixtures or feedingstuffs is not achievable by analysis and provided no experimental data. Therefore the EURL cannot evaluate nor recommend any method for official control to determine Bentonite-Montmorillonite in premixtures and feedingstuffs.

Further testing or validation of the methods to be performed through the consortium of National Reference Laboratories as specified by Article 10 (Commission Regulation (EC) No 378/2005) is not considered necessary.


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