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1.


   
    Comparison between the humic acids characteristics of two andisols of different age by: FT-IR and {1}H-NMR spectroscopy and py-FIMS [Text] / А. Baglieri [и др.] // Геохимия. - 2012. - № 2. - С. 164-174 : ил. - Библиогр.: с. 172-174 (48 назв. ) . - ISSN 0016-7525
УДК
ББК 26.301
Рубрики: Геология
   Геохимия--Европа--Италия--Этна, вулкан

Кл.слова (ненормированные):
органические вещества -- гуминовые кислоты -- почвы -- тефра -- вулканы -- пиролиз -- ядерный магнитный резонанс -- масс-спектрометрия -- спектроскопия -- ИК-Фурье спектроскопия
Аннотация: Mt Etna (Italy) is the highest, active volcano in Europe. Thanks to the availability of descriptive documents and maps, it is possible to date the formation of several Etna soils. We evaluated the effect of soil formation age on the composition of the soil organic matter (SOM) and humic acids (HAs) from two Etna andisols of different ages but having the same vegetation (Castanea saliva) and pedogenetic substrate (tephra). The characterization of the SOM and the HAs was carried out by elementary and functional group analysis, UV-visible spectrophotometry, Fourier Transform InfraRed (FT-IR) and {1}H-Nuclear Magnetic Resonance ({1}H-NMR) spectroscopies, and Pyrolysis - Field Ionization Mass Spectrometry (py-FIMS). Data showed that the age of the soil cannot be considered as influencing the chemical composition of the SOM. However higher volatilisation temperatures, for some compound classes, indicate the presence of more thermally-stable, organic molecules, therefore a more mature organic matter, or an organic component more greatly bound to the mineral component in the older soil. Finally the HA extracted from old soil contains a lower quantity of aliphatic compounds and a greater quantity of carbohydrate and aromatic molecules than the HA extracted from young soil.


Доп.точки доступа:
Baglieri, А.; Gennari, М.; Ioppolo, А.; Leinweber, Р.; Negre, М.

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2.


   
    Determination of point of zero charge of PILCs with single and mixed oxide pillars prepared from Tunisian-smectite [Text] / S. Arfaoui [и др.] // Геохимия. - 2012. - № 5. - С. 494-501 : ил. - Библиогр.: с. 500-501 (34 назв.) . - ISSN 0016-7525
УДК
ББК 26.301
Рубрики: Геология
   Геохимия--Европа--Италия--Этна, вулкан

Кл.слова (ненормированные):
глины -- потенциометрическое титрование -- точка нулевого заряда -- смектиты -- оксид хрома -- алюминий -- химические свойства -- физические свойства -- текстурные свойства -- вулканы -- нулевые заряды
Аннотация: Different pillared interlayer clays (PILCs) with single oxide pillars of Cr and Al and mixed oxide pillars of these metals have been prepared from a Tunisian purified smectite (Hp) : Several Al/metal, OH/metal and metal/clay ratios were used in order to investigate the effect on the chemical and physical properties, specifically the point of zero charge of the synthesized pillared clays. These chromium pillared clays compounds at n meq (Nitrate) and at n meq (Chlorite) are noted pillared clay Hp (20, 40, 60) [NO[3]] and pillared clays Hp (20, 40, 60) [Cl]. The structure of the pillared materials are studied by XRD and cationic exchange capacity, the textural property are investigated by the specific surface area S[BET]. The acid-base chemistry "surface acidity" of these products was analysed by using acid-base potentiometric in order to determine the PZC of each sample. The resulting materials exhibited basal spacings in the range of 13. 96-21. 13 A, with high surface areas (105. 8-198 m{2} g[-1]). Pillared clays prepared from Tunisian purified smectite showed an increase of basal spacings and surface areas. A relatively strong interaction between metal and aluminium in the pillars was observed. The samples are studied by acid-base potentiometric. This experimental method is used to determine the point of zero charge (PZC). The PZC values of the edge sites are 8. 2 for Tunisian purified smectite and 6. 8; 5. 9; 5. 19; 6. 84; 5. 86; 5. 73; 6. 78; 7. 56 for the differents samples respectively: Hp (20, 40, 60 meq) [NO[3]]; Hp (20, 40, 60 meq) [Cl]; Hp-Cr/Al; Hp-Al.


Доп.точки доступа:
Arfaoui, S.; Hamdi, N.; Frini-Srasra, N.; Srasra, E.

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