The aluminium content of water extracts is an important aspect for the food safety of paper board, as the content indicates the ability of the paper board material to transfer aluminium to the packaged food product. Aluminium intake in humans and its health effects have been discussed for many years as some research has seen potential links between, among other things, high aluminium levels in the brain and the development of hereditary Alzheimer's.BfR's method and recommendation is the one that is generally followed by producers around the world, as there is no common international law. The method involves leaving small pieces of the paper board in Milli-Q water for 24 hours, before a content determination of Al is made in the formed water extract. In 2021, BfR halved its recommended limit for aluminium in aqueous extracts from 2 mg/L to 1 mg/L. For Stora Enso Skoghall, this led to some of their paper board grades not meeting this limit.A specific liquid packaging board grade that previously did not meet BfR's new limit was selected and alum as a flocculant was replaced with PAC, among other things. The aim was to investigate whether the change in flocculation chemical, as well as varying dosages, could affect the Al content in water extracts and whether PAC could possibly result in a lower Al content. The method for the water extracts and their effect on the final Al content have also been investigated further. This is done by performing the BfR method with artificial tap water as well, and then comparing the Al content in these extracts.PAC as a flocculant instead of alum did not result in lower levels of Al in the water extracts. Variations in dosage and production without aluminium-containing flocculants also did not significantly affect the Al content of the extracts. The type of water used in the analysis turned out to play a major role in how much aluminium migrated from the board. All samples extracted in artificial tap water resulted in Al levels less than the 1 mg/L limit. For the majority of the samples extracted in Milli-Q water, the Al levels were instead closer to 2 mg/L. The difference in Al content between the water extracts is believed to be mainly due to differences in pH and thus varying amounts of soluble aluminium.The results showed a relatively large variation between the two external laboratories used. This is believed to be mainly due to variations in method and measuring equipment, but one must also consider the small sample size that was tested and what variations it entails.
| Identifer | oai:union.ndltd.org:UPSALLA1/oai:DiVA.org:kau-90300 |
| Date | January 2022 |
| Creators | Cassel, Hanna |
| Publisher | Karlstads universitet, Avdelningen för kemiteknik |
| Source Sets | DiVA Archive at Upsalla University |
| Language | English |
| Detected Language | English |
| Type | Student thesis, info:eu-repo/semantics/bachelorThesis, text |
| Format | application/pdf, application/pdf |
| Rights | info:eu-repo/semantics/openAccess, info:eu-repo/semantics/openAccess |
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