L-lysine monohydrochloride - 3c322IV, L-lysine sulphate - 3c329

Executive Summary

In the current application an authorisation is sought under Article 4(1) for L-lysine monohydrochloride and L-lysine sulphate produced by fermentation with Corynebacterium glutamicum CGMCC 17927, under the category/functional group 3(c) 'nutritional additives'/'amino acids, their salts and analogues', according to Annex I of Regulation (EC) No 1831/2003. The authorisation is sought for all animal species.
According to the Applicant, the minimum L-lysine content for L-lysine monohydrochloride is 78.8 % (w/w) while the content of L-lysine for L-lysine sulphate is 55.0 % (w/w).
The two forms of the feed additive are intended to be added directly into feedingstuffs or through complementary feed, premixtures and water without any recommended inclusion levels. Furthermore, no minimum or maximum contents have been proposed by the Applicant.
For the quantification of lysine in the feed additive, premixtures, feedingstuffs and water the Applicant proposed the ring-trial validated method EN ISO 13903:2005. This method is equivalent to the ring-trial validated European Union method (Commission Regulation (EC) No 152/2009) based on ion-exchange chromatography (IEC) coupled with post-column derivatisation and optical (visible) (VIS) detection. This method, designed only for the analysis of amino acids in premixtures and feedingstuffs, does not distinguish between the salts and the amino acid enantiomers. The following performance characteristics were reported for the quantification of total lysine: RSDr ranging from 2.1 to 2.8 % and RSDR ranging from 3.0 to 6.7 %.
However, the EURL is aware of the ring-trial validated method EN ISO 17180:2013 based on ion-exchange chromatography (IEC) coupled with post-column derivatisation and optical (visible or fluorescence) detection (IEC-VIS/FLD). It applies for products containing more than 10 % of amino acid and, as the previous method, does not distinguish between the salts of amino acids and cannot differentiate between enantiomers. The following performance characteristics are reported: a relative standard deviation for repeatability (RSDr) ranging from 0.7 to 1.7 % and a relative standard deviation for reproducibility (RSDR) ranging from 1.5 to 2.5 %. Furthermore, the EURL identified the "L-lysine monohydrochloride monograph" of the Food Chemical Codex (FCC) for the identification of L-lysine monohydrochloride in the feed additive and the generic European Pharmacopoeia monograph (Ph. Eur. 20301) for the identification of sulphate ions in the feed additive.
Based on the performance characteristics available, the EURL recommends for official control (i) the "L-lysine monohydrochloride monograph" of the Food Chemical Codex (FCC) for the identification of L-lysine monohydrochloride in the feed additive; (ii) the European Pharmacopoeia monograph (Ph. Eur. 01/2008:20301) for the identification of the sulphate ions in the feed additive (L-lysine sulphate); (iii) the ring-trial validated method EN ISO 17180:2013 based on ion-exchange chromatography coupled with post-column derivatisation and optical detection (IEC-VIS/FLD) to quantify free lysine in the feed additives and premixtures (containing more than 10 % lysine); (iv) the European Union method based on ion-exchange chromatography coupled with post-column derivatisation and optical detection (IEC-VIS) for the quantification of lysine in premixtures and feedingstuffs; and (v) the ion-exchange chromatography coupled with post-column derivatisation and optical detection (IEC-VIS/FLD) or coupled with post-column derivatisation and optical detection (IEC-VIS) methods for the quantification of lysine in 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, as last amended by Regulation (EU) 2015/1761) is not considered necessary.

Recommended Method

as of:

-Commission Implementing Regulation (EU) 2023/1163

For the identification of L-lysine monohydrochloride in the feed additive: 

Food Chemical Codex ‘L-lysine monohydrochloride monograph’

For the identification of sulphate in the feed additive (L-lysine sulphate): 

European Pharmacopoeia monograph 20301

For the quantification of lysine in the feed additives and premixtures (containing more than 10 % lysine): 

ion-exchange chromatography coupled with post-column derivatisation and optical detection (IEC- VIS/FLD) – EN ISO 17180

For the quantification of lysine in premixtures and compound feed: 

ion-exchange chromatography coupled with post-column derivatisation and optical detection (IEC-VIS), Commission Regulation (EC) No 152/2009 (Annex III, F) 

For the quantification of lysine in water: 

ion-exchange chromatography coupled with post-column derivatisation and optical detection (IEC-VIS/FLD); or 

ion-exchange chromatography coupled with post-column derivatisation and optical detection (IEC-VIS)