{"?xml":{"@version":"1.0"},"edm:RDF":{"@xmlns:dc":"http://purl.org/dc/elements/1.1/","@xmlns:edm":"http://www.europeana.eu/schemas/edm/","@xmlns:wgs84_pos":"http://www.w3.org/2003/01/geo/wgs84_pos","@xmlns:foaf":"http://xmlns.com/foaf/0.1/","@xmlns:rdaGr2":"http://rdvocab.info/ElementsGr2","@xmlns:oai":"http://www.openarchives.org/OAI/2.0/","@xmlns:owl":"http://www.w3.org/2002/07/owl#","@xmlns:rdf":"http://www.w3.org/1999/02/22-rdf-syntax-ns#","@xmlns:ore":"http://www.openarchives.org/ore/terms/","@xmlns:skos":"http://www.w3.org/2004/02/skos/core#","@xmlns:dcterms":"http://purl.org/dc/terms/","edm:WebResource":[{"@rdf:about":"http://www.dlib.si/stream/URN:NBN:SI:DOC-MOLGX8NI/4075f9cc-a733-4da5-87dd-3d4b4a4fa7b4/PDF","dcterms:extent":"812 KB"},{"@rdf:about":"http://www.dlib.si/stream/URN:NBN:SI:DOC-MOLGX8NI/e7604122-0846-483b-b070-f01c2885d7fb/TEXT","dcterms:extent":"25 KB"},{"@rdf:about":"http://www.dlib.si/stream/URN:NBN:SI:DOC-MOLGX8NI/2a6a527f-21dd-4d3d-bc7f-a970d67807b8/PDF","dcterms:extent":"797 KB"}],"edm:TimeSpan":{"@rdf:about":"1998-2025","edm:begin":{"@xml:lang":"en","#text":"1998"},"edm:end":{"@xml:lang":"en","#text":"2025"}},"edm:ProvidedCHO":{"@rdf:about":"URN:NBN:SI:DOC-MOLGX8NI","dcterms:isPartOf":[{"@rdf:resource":"https://www.dlib.si/details/URN:NBN:SI:spr-KC6O72BG"},{"@xml:lang":"sl","#text":"Acta chimica slovenica"}],"dcterms:issued":"2019","dc:creator":["Brovč, Ema Valentina","Mravljak, Janez","Pajk, Stane","Šink, Roman"],"dc:format":[{"@xml:lang":"sl","#text":"številka:4"},{"@xml:lang":"sl","#text":"letnik:66"},{"@xml:lang":"sl","#text":"str. 934-943"}],"dc:identifier":["ISSN:1580-3155","COBISSID_HOST:4819313","URN:URN:NBN:SI:doc-MOLGX8NI"],"dc:language":"en","dc:publisher":{"@xml:lang":"sl","#text":"Slovensko kemijsko društvo"},"dc:subject":[{"@xml:lang":"en","#text":"acid number"},{"@xml:lang":"en","#text":"degradation"},{"@xml:lang":"en","#text":"fatty acids"},{"@xml:lang":"sl","#text":"maščobne kisline"},{"@xml:lang":"en","#text":"nuclear magnetic resonance"},{"@xml:lang":"sl","#text":"Nuklearna magnetna resonanca"},{"@xml:lang":"sl","#text":"polisorbati"},{"@xml:lang":"en","#text":"polysorbates"}],"dcterms:temporal":{"@rdf:resource":"1998-2025"},"dc:title":{"@xml:lang":"sl","#text":"Comparison of the NMR and the acid value determination methods for quality control of input polysorbates|"},"dc:description":[{"@xml:lang":"sl","#text":"Polysorbates (PS) are the most common non-ionic surfactants used in protein formulations. Their degradation has been studied intensively in recent years. Ester bond hydrolysis is one of many pathways of PS degradation that can lead to accumulation of free fatty acids (FFAs) and particle formation. The distribution and quantity of FFAs in PSs impacts directly on product quality. Characterization of input PS is highly relevant, because the initial content of FFAs differs greatly between manufacturers. The purpose of this study was to set up a quick and simple analytical method for the quantitative evaluation of FFAs in PS. The content of FFAs was measured for selected PS 20 and 80, using two methods, 1H nuclear magnetic resonance spectroscopy (1H NMR) and the European pharmacopoeia method for determining acid value (IA). These methods have been evaluated using the method of standard addition and, based on the results, they are interchangeable. It was concluded that 1H NMR is a useful tool for quality control of input PS and a rapid method for indicating the rate of PS degradation by hydrolysis and oxidation. Further, a newly discovered impurity in PS raw material, the long chain ketone 12-tricosanone, can be identified using 1H NMR"},{"@xml:lang":"sl","#text":"Polisorbati (PS) so najpogosteje uporabljene neionske površinsko aktivne snovi v formulacijah s proteini. Njihovo razgradnjo so v zadnjih letih intenzivno proučevali. Hidroliza estrske vezi je ena od številnih razgradnih poti polisorbatov, ki lahko vodi v kopičenje prostih maščobnih kislin (FFAs) in v tvorbo delcev. Razporeditev in količina FFAs v PS neposredno vplivata na kakovost končnega izdelka. Karakterizacija vhodnega PS je izredno pomembna, saj se začetna vsebnost FFAs med različnimi proizvajalci zelo razlikuje. Namen naše študije je bil razviti hitro in enostavno metodo za kvantifikacijo FFAs v PS. Vsebnost FFAs smo izmerili izbranim vzorcem PS 20 in 80 z uporabo dveh metod, z metodo protonske jedrske magnetne resonančne spektroskopije (1H NMR) in s farmakopejsko metodo določanja kislinskega števila (IA). Metodi smo ovrednotili z uporabo metode standardnega dodatka in na podlagi dobljenih rezultatov ugotovili, da sta metodi zamenljivi. Zaključili smo, da je 1H NMR uporabna metoda za kontrolo kakovosti vhodnih PS in hitra metoda za spremljanje razgradnje PS s hidrolizo in oksidacijo. Tudi novo odkrito nečistoto v vhodnem PS, dolgoverižni keton 12-trikozanon, lahko identificiramo z uporabo 1H NMR"}],"edm:type":"TEXT","dc:type":[{"@xml:lang":"sl","#text":"znanstveno časopisje"},{"@xml:lang":"en","#text":"journals"},{"@rdf:resource":"http://www.wikidata.org/entity/Q361785"}]},"ore:Aggregation":{"@rdf:about":"http://www.dlib.si/?URN=URN:NBN:SI:DOC-MOLGX8NI","edm:aggregatedCHO":{"@rdf:resource":"URN:NBN:SI:DOC-MOLGX8NI"},"edm:isShownBy":{"@rdf:resource":"http://www.dlib.si/stream/URN:NBN:SI:DOC-MOLGX8NI/4075f9cc-a733-4da5-87dd-3d4b4a4fa7b4/PDF"},"edm:rights":{"@rdf:resource":"http://creativecommons.org/licenses/by/4.0/"},"edm:provider":"Slovenian National E-content Aggregator","edm:intermediateProvider":{"@xml:lang":"en","#text":"National and University Library of Slovenia"},"edm:dataProvider":{"@xml:lang":"sl","#text":"Slovensko kemijsko društvo"},"edm:object":{"@rdf:resource":"http://www.dlib.si/streamdb/URN:NBN:SI:DOC-MOLGX8NI/maxi/edm"},"edm:isShownAt":{"@rdf:resource":"http://www.dlib.si/details/URN:NBN:SI:DOC-MOLGX8NI"}}}}