L-lysine monohydrochloride - 3c322iii, L-lysine sulphate - 3c328

In the current application authorisation is sought under Article 4(1) for L-lysine monohydrochloride and L-lysine sulphate produced by fermentation with Corynebacterium glutamicum CGMCC 14498, 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. Authorisation is sought for all animal species. 

According to the Applicant, L-lysine monohydrochloride has a minimum purity (mass fraction on dry matter basis) of 98.5 % and 78.8 % with respect to the L-lysine content, respectively, while L-lysine sulphate has a minimum purity of 73.0 % and 55.0 % with respect to the L-lysine content, respectively. 

The two forms of the feed additive are intended to be added directly into feedingstuffs or through complementary feed, premixtures and water. However the Applicant did not propose any minimum or maximum content of L-lysine in feedingstuffs.

For the quantification of lysine in the feed additive the Applicant proposed the ring-trial validated method EN ISO 17180:2013 based on ion-exchange chromatography coupled to visible or fluorescence detection (IEC-VIS/FLD). This standard method does not distinguish between the salts of amino acids and cannot differentiate between enantiomers. It applies for products containing more than 10 % of amino acid. The following performance characteristics are reported: a relative standard deviation for repeatability (RSD_r) ranging from 0.7 to 1.7 % and a relative standard deviation for reproducibility (RSD_R) ranging from 1.5 to 2.5 %. In addition, 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 feed additive. 

For the quantification of lysine in premixtures, feedingstuffs and water the Applicant suggested using the ring-trial validated European Union method (Commission Regulation (EC) No 152/2009) based on IEC coupled with photometric detection (IEC-VIS). 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: RSD_r ranging from 2.1 to 2.8 % and RSD_R ranging from 3.0 to 6.7 %. Furthermore, as concluded in previous amino acids reports, the EURL also considers the IEC-VIS/FLD procedure described above as fit-for-purpose for the determination of lysine in water. 

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 sulphate ions in feed additive; (iii) the ring-trial validated method EN ISO 17180:2013 based on IEC-VIS/FLD to quantify free lysine in the feed additive and premixtures (containing more than 10 % lysine); (iv) the European Union method based on IEC-VIS for the quantification of lysine in premixtures and feedingstuffs; and (v) the ion-exchange chromatography methods coupled with post-column derivatisation and optical detection (IEC-VIS/FLD) or coupled with post-column derivatisation and photometric detection (IEC-VIS) 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) 2022/1525

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:

— 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, compound feed and feed materials:

— 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 or IEC-VIS/FLD)