1,721,115 research outputs found
Sovranità alimentare e crisi ambientale
No full textQuesto volume affronta il tema della sostenibilità ambientale degli scambi commerciali nel settore alimentare andando ad indagare uno degli elementi rilevanti dal punto di vista ambientale: l’impatto in termini di emissioni in atmosfera del consumo di prodotti alimentari provenienti da mercati extranazionali e dai passaggi che prodotti anche di origine nazionale sono costretti a fare
ALTERNATIVE METHOD FOR CARBOXYL GROUP DETERMINATION IN HUMIC SUBSTANCES
No full textA new precipitation titration method, employing cetyltrimethylammonium (CTA+), is proposed for analysis of carboxyl groups of humic substances in solution. The method was tested with polyphenol-polycarboxylic acids standard solutions: recovery factors ranged from 0.94 to 1.09. Results obtained by performing precipitation of humic acids samples at pH = 9.8 and at 7.0 are compared with those obtained by the Ca-acetate method. The difference between the number of COOH per unit weight of humic preparation calculated by precipitation with CTA+ at pH = 7.0 and by the Ca-acetate exchange reaction ranged between 1 and 45%. In most samples overestimation of COOH groups by the Ca-acetate method appears to be higher than the mean relative error of the CTA+ precipitation method (5%). Key words: Carboxylic group determination, humic substances, cetyltrimethylammoniu
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