Zinc compounds (3b601; 3b602; 3b603; 3b604; 3b605; 3b606; 3b612; 3b607; 3b608)

Recommended Method

as of:

- Commission Implementing Regulation (EU) 2016/1095

For the quantification of the zinc acetate dihydrate in the feed additive:

— titration with sodium edetate (European Pharmacopoeia Monograph 1482)

For the quantification of the zinc chloride anhydrous in the feed additive:

— titration with sodium edetate (European Pharmacopoeia Monograph 0110)

— ICP-AES CEN method (EN ISO 11885)

For the quantification of the zinc oxide in the feed additive:

— titration with sodium edetate (European Pharmacopoeia Monograph 0252)

For the quantification of the zinc sulphate heptahydrate in the feed additive:

— titration with sodium edetate (European Pharmacopoeia Monograph 0111)

For the quantification of the zinc sulphate monohydrate in the feed additive:

— titration with sodium edetate (European Pharmacopoeia Monograph 2159)

For the quantification of amino acid content in the feed additive:

— ion exchange chromatography method with post-column derivatisation and UV or fluorescence detection: Commission Regulation (EC) No 152/2009 (Annex III, F)

For the quantification of protein hydrolysates content in the feed additive:

— ion exchange chromatography method with post-column derivatisation and UV or fluorescence detection: Regulation (EC) No 152/2009 (Annex III, F)

For the determination of chelated Zinc content in the feed additive:

— Fourier Transformed Infrared (FTIR) spectroscopy followed by multivariate regression methods

For the quantification of the glycine content in the feed additive:

— ion exchange chromatography method with post-column derivatisation and UV or fluorescence detection: Regulation (EC) No 152/2009 (Annex III, F)

For the quantification of the glycine content in the feed additive:

— ion exchange chromatography method with post-column derivatisation and UV or fluorescence detection: Regulation (EC) No 152/2009 (Annex III, F)

For the quantification of total zinc in the feed additives and premixtures:

— EN 15510: Inductively Coupled Plasma — Atomic Emission Spectrometry (ICP- AES), or

— EN 15621: Inductively Coupled Plasma — Atomic Emission Spectrometry (ICP- AES) after pressure digestion

For the quantification of total zinc in feed materials and compound feed:

— Regulation (EC) No 152/2009 — Atomic Absorption Spectrometry (AAS); or

— EN 15510: Inductively Coupled Plasma — Atomic Emission Spectrometry (ICP- AES); or

— EN 15621: Inductively Coupled Plasma — Atomic Emission Spectrometry (ICP- AES) after pressure digestion

Executive Summary

In the current application authorisation is sought under articles 4(1) and 10(2) for zinc acetate dihydrate¹, zinc chloride anhydrous¹, zinc oxide^{1, 5}, zinc sulphate heptahydrate¹, zinc sulphate monohydrate^{1, 2, 3}, zinc chelate of amino acids hydrate^{1, 4} and zinc chelate of glycine hydrate¹ under the category/functional group 3(b) of "nutritional additives"/"compounds of trace elements", according to the classification system of Annex I of Regulation (EC) No 1831/2003. According to the Applicants: - zinc acetate dihydrate is white solid with a minimum content of 29.6 % total zinc; - zinc chloride anhydrous is white to slightly coloured solid with a minimum content of 46 % total zinc; - zinc oxide is white to dark green or beige brownish solid with a minimum content of 72 % total zinc; - zinc sulphate heptahydrate is a white solid with a minimum content of 22 % total zinc; - zinc sulphate monohydrate is a white to cream coloured solid with a minimum content of 34 % total zinc; - zinc chelate of amino acid hydrate is beige to dark tanned solid with a minimum content of 10 % total zinc; and - zinc chelate of glycine hydrate is white to cream coloured solid with a minimum content of 24 % total zinc. Specifically, authorisation is sought for the use of these feed additives for all categories and species. For the identification and quantification of the inorganic zinc compounds (i.e. zinc acetate dihydrate, zinc chloride anhydrous, zinc oxide, zinc sulphate heptahydrate and zinc sulphate monohydrate) in the feed additive, the EURL recommends for official control the relevant European Pharmacopoeia Monograph (1482, 0110, 0252, 0111 and 2159) methods, based on complexometric titration with 0.1 M sodium EDTA using xylenol orange triturate as indicator. For the quantification of "amino" content in the amino zinc chelates (i.e. zinc chelate of glycine hydrate and zinc chelate amino acids hydrate), the Applicant proposed - upon request from the EURL - the Community method based on High Performance Liquid Chromatography (HPLC) combined with post-column derivatisation using ninhydrin as derivatisation agent and photometric detection at 570 nm. The EURL considers the Community method suitable for the characterisation of the amino compounds in the frame of official control. For the determination of total zinc in all the feed additives, premixtures and feedingstuffs the Applicant submitted the CEN method (EN 15510), based on inductively coupled plasma atomic emission spectroscopy (ICP-AES). The following performance characteristics were reported: - a relative standard deviation of repeatability (RSD_r) ranging from 1.7 to 8.8 %; - a relative standard deviation for reproducibility (RSD_R) ranging from 5.0 to 19 %; and - a limit of quantification (LOQ) of 3 mg/kg. Furthermore, the Applicant identified an alternative CEN ring-trial validated method (CEN/TS 15621) based on ICP-AES after pressure digestion, for the determination of total zinc in the feed additive, premixtures and feedingstuffs. The following performance characteristics were reported for a feed for pigs, and for sheep, a rock phosphate, a mineral premix and a mineral mix, where the total zinc content ranged from 26.6 to 3618 mg/kg: - RSD_r ranging from 1.5 to 5.4 %; - RSD_R ranging from 2.7 to 22 %; and - LOQ = 1 mg/kg feedingstuffs. Finally, the Applicant suggested the Community method for the determination of total zinc in feedingstuffs, with limited method performance characteristics provided. However, the UK Food Standards Agency organised a comparative trial based on the above mentioned Community method and reported precisions (RSD_r and RSD_R) for feedingstuffs ranging from 1.0 to 9.5 %. Based on these acceptable method performance characteristics the EURL recommends for official control the ICP-AES CEN methods (EN 15510 and CEN/TS 15621) to determine total zinc content by in the feed additive and premixtures. As for the determination of total zinc content in feedingstuffs, the EURL recommends for official control the Community method based on AAS together with the above mentioned ICP-AES CEN methods. For the quantification of total zinc in water the Applicant² submitted the ring trial validated method EN ISO 11885, based on ICP-AES. The following performance characteristics are reported: - RSD_r ranging from 1.5 to 2.4 %; - RSD_R ranging from 4.9 to 5.9 %; and LOQ = 1 μg/L. Based on these acceptable method performance characteristics the EURL recommends for official control the CEN methods (EN ISO 11885) to quantify total zinc content by ICP-AES in the water. 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.

¹ FAD-2010-0142; ² FAD-2010-0228; ³ FAD-2010-0059; ⁴ FAD-2010-0063; ⁵FAD-2010-0072

- PLEASE NOTE THAT THE ORIGINAL REPORT HAS BEEN AMENDED -