Sodium benzoate (1k301)

Recommended Method

as of:

- Commission Implementing Regulation (EU) 2016/2023

For the determination of sodium benzoate:

- titrimetric method (01/2008:0123 of European Pharmacopoeia)

Executive Summary

In the current application authorisation is sought under article 10(2) for sodium benzoate under the category / functional group 1(k) of 'technological additives'/'silage additives', according to the classification system of Annex I of Regulation (EC) No 1831/2003. Specifically, authorisation is sought for the use of the feed additive for bovines, sheep, pigs, poultry, rabbits, horses, goats.

According to the Applicant, the feed additive is a white, odourless, solid substance. The feed additive consists of sodium benzoate, with a minimum purity of 99.5 %. The feed additive is intended to be used in silage, with a proposed maximum level of 2.4 g/kg silage.

For the determination of sodium benzoate in the feed additive the Applicant proposed the European Pharmacopoeia Monograph (01/2008:0123), where: - identification is based on the sodium and on the benzoate reactions, while - quantification is based on the titration of sodium benzoate with 0.1 M perchloric acid, using naphtholbenzein as an indicator.

Even though no performance characteristics are provided, the EURL recommends for official control the above mentioned European Pharmacopoeia Monograph to determine sodium benzoate in the feed additive.

For the quantification of sodium benzoate in silage the Applicant submitted a single-laboratory validated and further verified method, based on high performance liquid chromatography with UV detection (HPLC-UV). The following performance characteristics were reported for sodium benzoate concentrations – ranging from 215 to 2620 mg/kg: - a relative standard deviation for repeatability (RSD_r) ranging from 0.6 % to 12 %; - a recovery rate (R_rec) ranging from 103 to 109 %; and - a limit of quantification (LOQ) of 125 mg/kg silage.

Based on the performance characteristics presented, the EURL considers the single laboratory validated and further verified HPLC-UV method suitable for the determination of sodium benzoate in silage. However, the unambiguous determination of the content of sodium benzoate added to silage cannot be performed satisfactorily due to intrinsic properties of silage matrice. Therefore, the EURL cannot recommend this method for official control to determine added sodium benzoate in silage.

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.