title: Sequestration of biogenic amines by alginic and fulvic acids.
abstract: The interaction of natural (alginic and fulvic acids) and synthetic (polyacrylic acid 2.0 kDa) polyelectrolytes with some protonated polyamines [diamines: ethylendiamine, 1,4-diaminobutane (or putrescine), 1,5-diaminopentane (or cadaverine); triamines: N-(3-aminopropyl)-1,4-diaminobutane (or spermidine), diethylenetriamine; tetramine: N,N'-bis(3-aminopropyl)-1,4-diaminobutane (or spermine); pentamine: tetraethylene-pentamine; hexamine: pentaethylenehexamine] was studied at T=25 degrees C by potentiometry and calorimetry. Measurements were performed without supporting electrolyte, in order to avoid interference, and results were reported at I=0 mol L(-)(1). For all the systems, the formation of (am)L(2)H(i) species was found (am=amine; L=polyelectrolyte; i=1...4, depending on the amine considered). The stability of polyanion-polyammonium cation complexes is always significant, and for high-charged polycations, we observe a stability comparable to that of strong metal complexes. For example, by considering the formation reaction (am)H(i)+2L=(am)L(2)H(i) we found log K(i)=6.0, 6.5 and 10.8 for i=1, 2 and 3, respectively, in the system alginate-spermidine. Low and positive formation DeltaH(degrees) values indicate that the main contribution to the stability is entropic in nature. The sequestering ability of polyelectrolytes toward amines was modelled by a sigmoid Boltzman type equation. Some empirical relationships between stability, charges and DeltaG(degrees) and TDeltaS(degrees) are reported. Mean values per salt bridge of formation thermodynamic parameters (DeltaX(degrees) (n)) are DeltaG(degrees) (n)=-5.8+/-0.4, DeltaH degrees (n)=0.7+/-0.5 and TDeltaS(degrees) (n)=6.5+/-0.5 kJmol(-)(1) for all the systems studied in this work.
authors.affiliation: Dipartimento di Chimica Inorganica, Chimica Analitica e Chimica Fisica, Università di Messina, Salita Sperone 31, I-98166, Messina (Vill. S. Agata), Italy.
authors.forename: Concetta
authors.initials: C
authors.lastname: De Stefano
authors.forename: Antonio
authors.initials: A
authors.lastname: Gianguzza
authors.forename: Daniela
authors.initials: D
authors.lastname: Piazzese
authors.forename: Nunziatina
authors.initials: N
authors.lastname: Porcino
authors.forename: Silvio
authors.initials: S
authors.lastname: Sammartano
mesh_terms: D000464:Alginates / Q000737:chemistry*; D001578:Benzopyrans / Q000737:chemistry*; D001679:Biogenic Amines / Q000737:chemistry*; D002264:Carboxylic Acids / Q000737:chemistry; D004573:Electrolytes / Q000737:chemistry; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D008433:Mathematics; D008956:Models, Chemical; D011073:Polyamines / Q000737:chemistry; D000071228:Polyelectrolytes; D011108:Polymers / Q000737:chemistry; D011522:Protons; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D013816:Thermodynamics
chemical_list: D000464:Alginates; D001578:Benzopyrans; D001679:Biogenic Amines; D002264:Carboxylic Acids; D004573:Electrolytes; D020723:Glucuronic Acid; D006603:Hexuronic Acids; D011073:Polyamines; D000071228:Polyelectrolytes; D011108:Polymers; D011522:Protons; D000644:Quaternary Ammonium Compounds; C005023:fulvic acid