EXTRACTION OF RESIDUAL HEAVY METALS FROM COMMERCIAL CHITOSAN AND APPROACH TO PREPARATION OF OLIGOCHITOSAN HYDROCHLORIDEстатья
Статья опубликована в высокорейтинговом журнале
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Дата последнего поиска статьи во внешних источниках: 20 мая 2019 г.
Аннотация:For biomedical applications, chitosan and oligochitosan must be appropriately characterized and meet pharmacological requirements in terms of contamination by residual heavy metals.
In this work, a series of commercial chitosans was analyzed by ICP-MS method, and high concentration of Fe (44-382 ppm), Cr (3.1-35.5 ppm) and Ni (0.33-7.91 ppm) exceeding pharmacologically acceptable level was found. It was shown that as a chelating agent EDTA was an ineffective remedy for solid-phase extraction of residual heavy metals from chitosan. It was proposed that corrosion of stainless steel apparatus in the process of chitin deacetylation contributed to chitosan contamination by heavy metals. A two-step treatment of chitosan with hydrochloric acid allowed remediation of chitosan and preparation of oligochitosan hydrochloride with molecular weight 5-16 kDa and acceptable level of Fe<10, Cr<1 and Ni<1 ppm.