The use of ionic chromatography in determining the contamination of sugar by-products by nitrite and nitrate

- We validated the HPAEC for determining the content of NO2 and NO3 in feed products.
- We evaluated the content of NO2 and NO3 in beet pulp, raw beet juice and molasses.
- Some of analysed samples would not meet the requirements of Directive 2010/6/EU.

In 2010, the Directive on undesirable substances in animal feed entered into force and for the first time was laid down a maximum limit for nitrite content in sugar industry feed materials such as molasses and beet pulp. Due to a lack of suitable analytical methods for nitrite determination, this study was developed with the aim to standardize a nitrite analytical method in by-products from sugar industry.In this study high performance anion exchange chromatography with conductometric detection was used for determining nitrite and nitrate content of sugar by-products included in feed material.The study confirms the usefulness of the applied ion chromatographic method for the evaluation of the content of nitrite and nitrate in sugar by-products.The results showed that in many samples of beet pulp and molasses the content of “undesirable substances for animal feed” was below 15 mg kg−1 (expressed as sodium nitrate at 12% of moisture).