{"product_id":"humic-acid-von-mazin-halbos","title":"Humic Acid","description":"\u003cp\u003eEarlier studies in our laboratory indicated oxidation of humic acid by Fe(VI) but the quenching of fluorescence by a reaction product Fe(III) led to uncertainty about the extent of oxidation. The interactions of Fe(VI)\/Fe(III) with the humic acids (HAs) are investigated using synchronous scan fluorescence (SSF) spectroscopy, UV-Vis spectroscopy and DART-MS spectroscopy. In the fluorescence study, there was an immediate decrease in the SSF intensity after addition of both Fe(VI) and Fe(III) to all the HA mixtures, which suggested that there is a reaction between HAs with Fe(VI) as well as Fe(III). These reactions were further investigated quantitatively by UV-vis spectroscopy. The results show that the HAs oxidize immediately after the addition of Fe(VI). Also, HAs react with Fe(III), forming a complex between the functional groups of HA and Fe(III). These interactions were further investigated by with pH change and by DART-MS. The results show a greater number of lower m\/z peaks after mixing of HAs with Fe(VI) than before mixing, suggesting that the oxidation of the HAs by Fe(VI) leads to the fragmentation of these HAs.\u003c\/p\u003e\u003cdiv class=\"aw-variant-hidden-subtitle-div\" id=\"aw-variant-subtitle-9783330319523\"\u003e\u003ch3\u003e\u003c\/h3\u003e\u003c\/div\u003e","brand":"Libri","offers":[{"title":"Softcover - 9783330319523","offer_id":39419748810845,"sku":"9783330319523","price":49.9,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0940\/0622\/files\/08200807-73b9-49c3-8740-57d2c1969526.jpg?v=1773293833","url":"https:\/\/shop.autorenwelt.de\/products\/humic-acid-von-mazin-halbos","provider":"Autorenwelt Shop","version":"1.0","type":"link"}