Determination of fat-soluble vitamins in vegetable oils through microwave-assisted high-performance liquid chromatography

In this manuscript, a study of the effect of microwave radiation on the high-performance liquid chromatography separation of tocopherols and vitamin K1 was conducted. The novelty of the application was the use of a relatively low polarity mobile phase in which the dielectric heating effect was minimized to evaluate the nonthermal effect of the microwave radiation over the separation process. Results obtained show that microwave-assisted high-performance liquid chromatography had a shorter analysis time from 31.5 to 13.3 min when the lowest microwave power was used. Moreover, narrower peaks were obtained; hence the separation was more efficient maintaining or even increasing the resolution between the peaks. This result confirms that the increase in mobile phase temperature is not the only variable for improving the separation process but also other nonthermal processes must intervene. Fluorescence detection demonstrated better signal-to-noise compared to photodiode arrayed detection mainly due to the independent effect of microwave pulses on the baseline noise, but photodiode array detection was finally chosen as it allowed a simultaneous detection of nonfluorescent compounds. Finally, a determination of the content of the vitamin E homologs was carried out in different vegetable oils. Results were coherent with those found in the literature.

Anisotropy-magnetic susceptibility from the Krems Wachtberg archaeological Site (Austria) and high temperature susceptibility

The loess sediment embedding the main Gravettian layer at the Krems-Wachtberg archaeological site facilitates exceptional preservation. To gain insight in the sedimentation process before and after the Paleolithic settlement, the magnetic fabric (preferential orientation of magnetic particles) of loess of the Krems-Wachtberg site is investigated. Magnetic fabric properties clearly show an eolian origin of the loess, but may indicate some relocation in the meter above the cultural layer. The magnetic fabric properties can be divided into three intervals, the top interval shows lowest foliation and inconsistent magnetic fabric directions. The middle interval around the main cultural layer shows low foliation, but a clear preferential NW - SE direction of the lineation. This lineation is interpreted as preferential direction of the eolian loess accumulation from the South-East. The interval below ca. 0.5 m underneath the main find horizon shows a northeast-southwest lineation, but an imbrication suggesting that sediment accumulation occurred perpendicular to this direction, similar to the interval around the find horizon.

Magnetic properties of ODP Site 191-1179 sediments

As reported by Shipboard Scientific Party (2001b, doi:10.2973/odp.proc.ir.191.104.2001) in the Site 1179 chapter of the Initial Reports volume, Leg 191 Site 1179 is located on abyssal seafloor northwest of Shatsky Rise, ~1650 km east of Japan. This part of the Pacific plate was formed during the Early Cretaceous, as shown by northeast-trending M-series magnetic lineations that become younger toward the northwest (Larson and Chase, 1972, doi:10.1130/0016-7606(1972)83[3627:LMEOTW]2.0.CO;2; Sager et al., 1988, doi:10.1029/JB093iB10p11753; Nakanishi et al., 1989, doi:10.1029/1999JB900002). The site is situated on magnetic Anomaly M8 (Nakanishi et al., 1999, doi:10.1029/1999JB900002), corresponding to an age of ~129 Ma and the Hauterivian stage of the Early Cretaceous (Gradstein et al., 1994, doi:10.1029/94JB01889; 1995). The sediments recovered at Site 1179 are split into four lithostratigraphic units based on composition and color (Shipboard Scientific Party, 2001b, doi:10.2973/odp.proc.ir.191.104.2001). Unit I (0-221.52 meters below seafloor [mbsf]) is a dominantly olive-gray clay- and radiolarian-bearing diatom ooze. Unit II (221.52-246.0 mbsf) is a yellowish brown to light brown clay-rich and diatom-bearing radiolarian ooze. Unit III (246.0-283.53 mbsf) is composed of brown pelagic clay. Unit IV (283.53-377.15 mbsf) is composed of chert and some porcellanite; any softer sediments present were washed out of the core barrel by the fluid circulating during the coring process.

Calcium carbonate content and anisotropy of magnetic susceptibility of ODP Leg 172 sites

Sediments from Sites 1057 and 1061 of Ocean Drilling Program Leg 172 on the Blake Outer Ridge exhibit nearly isotropic magnetic susceptibility. Resolving the degree of anisotropy of magnetic susceptibility proved difficult in many samples because of the generally weak magnetic susceptibility of the sediments relative to the noise level of the susceptibility meters used. Lineation varies from 1.0 to 1.013 and foliation varies from 1.0 to 1.08 in the samples that pass rejection criteria. In general the foliation is better resolved than the lineation, particularly at Site 1061, where the foliation exhibits long-term trends that mimic the mean susceptibility. The changes in the foliation at this site are likely the result of changes in the magnetic mineralogy of the sediment. The poorly developed or absent magnetic fabric in the sediments overall can be attributed to high carbonate concentrations and to a circulation regime that was diffuse or with currents too weak to effectively align magnetic particles.

De termino Michaelis anno XXXIIII. regni Regis Henrici Sexti.

Numbered as leaves, printed as pages.

Catalecta rabbinica in usum scholarum privatarum edita /

Mode of access: Internet.

Isbrandi de Diemerbroeck ... Opera omnia anatomica et medica : partim jam antea excusa, sed plurimis locis ab ipso auctore emendata, & aucta, partim nondum edita /

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Elementos de medicina practica /

Mode of access: Internet.

Oeuvres de Monsieur de Montesquieu.

Contiene : Avertissement sur cette nouvelle edition ; Éloge de M. de Montesquieu par M. D'Alembert ; Analise de l'Esprit des Loix par M. D'Alembert ; Discours prononcé le 24 Janvier 1728 par M. de Montesquieu à l'Académie Françoise ; Livres I-XII inclusivement de l'Esprit des Loix

Essai sur les probabilités de la durée de la vie humaine d'où l'on déduit la maniere de déterminer les rentes viageres, tant simples qu'en tontines ... et accompagné d'un grand nombre de tables /

Mode of access: Internet.

Coleccion de las obras sueltas, assi en prosa, como en verso /

Relacion de las fiestas que la ... Villa de Madrid, hizo en la coronizacion de... San Isidro ... : p. VII-LXXIV, con port. propia ; La niñez de San Isidro ... : p. 1-74 ; La juventud de San Isidro ... : p. 75-148 ; Justa poética ... : p. 149-426.

Real Cedula de su Magestad y señores del consejo, sobre la reforma y arreglo del Colegio mayor de Santa Cruz de la Universidad de Valladolid.

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Real Cedula de su Magestad y señores del consejo, sobre la reforma y arreglo del Colegio mayor de Santiago el Zebedeo, llamado comunemente del Arzobispado de la Universidad de Salamanca.

Mode of access: Internet.

Recueil des planches du Dictionnaire de chimie et de métallurgie : faisant partie del'Encyclopédie Méthodique par ordre de matières ...

"Premier partie. Chimie" ; "Seconde partie. Métallurgie "