Estequiometría del complejo Carmín Boro

The nature of  the boron·carmine complex in solution is established· by three methods. These were the method of continuous variations by Job and modified by Vosburgh and Cooper, the mole ratio method proposed by Yoe and Jones, and the slope ratio method of Harvey and Manning and modified by Venkateswarlu and Raghava Rao. The results obtained by the three methods indicate that the empirical formula of  the boron complex is two atoms of boron to one molecule of the reagent

Determination of copper in different chloroplast preparations

The determination of total Cu is not often correlated with states of deficiency in plant material. This fact makes it necessary to look for biologically active Cu. Suspensions of thylakoid membranes and photosystem II particles, properly diluted with 13 mM nitric acid, were used for this purpose. The presence of a minute quantity of an antifoaming agent, such as 1-octanol, is essential when an aliquot of the slurry is injected into the graphite furnace of the atomic absorption spectrophotometer. Good agreement was obtained between our results and those obtained by a classical dry combustion method. Reproducibility was better than 5% when expressed as relative standard deviation.Ministerio de Educación y Ciencia (Spain)Peer reviewe

Copper binding sites associated with photosystem 2 preparations

Some steps in the isolation method of photosystem 2 (PS2)-enriched particles (BBY) influenced the Cu content of the final preparation. In particular, the centrifugation at 10 000 x g used to remove starch after Triton X-100 treatment of the thylakoids, yielded starch-free BBY with a low copper content. This contrasted with the high Cu content of the starch-containing BBY. Differences in Cu levels of both preparations seemed thus to be related to the starch content of the sample. Four unidentified proteins were found in the starch fraction. They are probably new copper binding sites in the photosynthetic cell.This work was supported by a grant from the Spanish DGICYT (Project PB 88-0092) and Dr.W.Schroder's stay in Granada by a grant of the Junta de Andalucia.Peer reviewe

Determination of trace-elements and their distribution in different fractions of the soil. II. Leached fersialitic soils with calcium reserves

31 páginas, 4 gráficas, 16 tablas, 2 perfiles, 15 referencias.[ES]: Los perfiles de dos suelos fersialíticos lavados con reserva cálcica se dividen en ocho diferentes fracciones, de acuerdo con el tamaño de partícula. Se determinan espectrográficamente en cada fracción de cada uno de los horizontes de los perfiles los elementos Ag, As, Ba, Be, Bi, Cd, Ca, Cr, Ga, Ge, Hg, In, La, Li, Mo, Mn, Ni, Pb, Rb, Sn, Sr, Th, Tl, V, W, y Zr. Los resultados muestran la contribución al total del suelo de cada fracción para cada uno de los elementos estudiados.[EN]: Two leached fersialitic soil profiles with calcium reserves are divided into eight different fractions according to the particle size. Ag, As, Ba, Be, Bi, Cd, Ca, Cr, Ga, Ge, Hg, In, La, Li, Mo, Mn, Ni, Pb, Rb, Sn, Sr, Th, Tl, V, W, and Zr are determined by spectrography in each fraction of each horizon of the profiles. The results show the contribution to the total of the soil of every fraction for each of the clements studied.Peer reviewe

Determination of trace-elements and their distribution in different fractions of the soil. VI.

29 páginas, 4 gráficas, 15 tablas, 2 perfiles. 14 referencias.[ES]: Ag, As, Ba, Be, Bi, Cd, Co, Cr, Cu, Ga, Ge, Hg, In, La, Li, Mo, Mn, Ni, Pb, Rb, Sn, Sr, Th, Tl, V. W, Y y Zr se determinan en los horizontes de dos suelos pardo-calizos, siguiendo un método espectrográfico semicuantitativo. Cada horizonte se dividió en ocho fracciones: 390 micras, estudiando el contenido en elementos-traza en cada una de ellas separadamente, ya que la fertilidad potencial está condicionada a la asociación con un determinado tamaño de partícula. Se ha realizado el estudio mineralógico de algunas fracciones para tratar de relacionar la presencia de cada elemento con la existencia de los minerales encontrados. Los resultados muestran la contribución al contenido total de los suelos de cada fracción para cada uno de los elementos estudiados.[EN]: Ag, As, Ba, Be, Bi, Cd, Co, Cr, Cu, Ga, Ge, Hg, In, La, Li, Mo, Mn, Ni, Pb, Rb, Sn, Sr, Th, Tl, V. W, Y and Zr are determined following a semiquantitative spectrographic method, in the horizons of two calcareous-brown soils. Each horizon was divided into eight fractions: 2, 2-10, 10-20, 20-48, 48-100, 100-200, 200-300 and 390 microns, and the trace-element content studied separately as potential fertility is subject to the association with a given particle size. The mineralogical study of some fractions has been carried out in order to relate the presence of each element to the existance of the minerals found. The results show the contribution to the total of the soils of every fraction for each of the elements studied.Peer reviewe

Determination of trace-elements and their distribution in different fractions of the soil. V. Rendzines

32 páginas, 4 gráficas, 2 perfiles, 18 tablas, 12 referencias.[ES]: Se determina espectro gráficamente el contenido total semicuantitativo de los elementos Ag, As, Ba, Be, Bi, Cd, Co, Cr, Cu, Ga, Ge, Hg, In, La, Li, Mo, Mn, Ni, Pb, Rb, Sb, Sn, Sr, Th, Tl, V, W, Y y Zr en los tres horizontes de dos suelos rendsinas. Por otra parte, cada horizonte se divide en ocho fracciones: < 2, 2-10, 10-20, 20-48, 48-100, 100-200, 200-390 y >390 micras, estudiando el contenido de elementos-traza en cada uno separadamente. El estudio mineralógico de las diferentes fracciones se ha llevado a cabo para relacionar, en lo posible, la presencia de cada elemento con la existencia de los minerales correspondientes. Los resultados muestran la contribución al total del suelo de cada fracción para cada uno de los elementos estudiados.[EN]: Semiquantitative total content of the elements Ag, As, Ba, Be, Bi, Cd, Co, Cr, Cu, Ga, Ge, Hg, In, La, Li, Mo, Mn, Ni, Pb, Rb, Sb, Sn, Sr, Th, Tl, V, W, Y and Zr is determined by spectrography in the three horizons of two rendzine soils. On the other hand, each horizon is divided into eight fractions: < 2, 2-10, 10-20, 20-48, 48-100, 100-200, 200-390 and >390 microns, and their trace-elements content studied separately. The mineralogical study of the different fractions has been carried out to relate the presence of each element to the existance of the corresponding minerals when it is possible. The results show the contribution to the total of the soil of every fraction for each of the elements studied.Peer reviewe

Determination of trace-elements and their distribution in different fractions of the soil. III. Leached fersialitic soil without calcium reserve

16 páginas, 2 gráficas, 7 tablas, 1 perfil, 8 referencias.[ES]: Se estudia un perfil de un suelo fersialítico, lavado sin reserva cálcica. Cada uno de los horizontes del perfil se separa en ocho diferentes fracciones, de acuerdo con el tamaño de partícula. Se determinan espectrográficamente en cada fracción los elementos Ag, As, Ba, Be, Bi, Cd, Co, Cr, Ga, Ge, Hg, In, La, Li, Mo, Mn, Ni, Pb, Rb, Sn, Sr, Th, Tl, V, W, y Zr. Los resultados muestras la contribución al total del suelo de cada fracción para cada uno de los elementos estudiados.[EN]: A leached fersialitic soil profile without ca1cium reserve is divided into eight different fractions according to the particle size. Ag, As, Ba, Be, Bi, Cd, Co, Cr, Ga, Ge, Hg, In, La, Li, Mo, Mn, Ni, Pb, Rb, Sn, Sr, Th, Tl, V, W and Zr are determined by spectrography in each fraction of each horizon of the profile. The results show the contribution to the total of the soil of every fraction for each of the elements studied.Peer reviewe

Determination of trace-elements and their distribution in different fractions of the soil. IV. Meridional brown earth

15 páginas, 2 gráficas, 7 tablas, 7 referencias.[ES]: Los dos horizontes más superficiales de una tierra parda meridional se separan en ocho distintas fracciones: 390 micras, determinándose espectrográficamente los elementos Ag, As, Ba, Be, Bi, Cd, Cr, Cu, Ga, Ge, Hg, In, La, Li, Mo, Mn, Ni, Pb, Rb, Sb, Sn, Sr, Th, Tl, V, W, y Zr en cada una de las mencionadas fracciones. En todos los casos posibles se relaciona la presencia de aquellos elementos con la composición mineralógica de cada una de las fracciones. Los resultados, por último, muestran la contribución al total del suelo de cada: fracción para cada uno de los elementos estudiados.[EN]: A "meridional brown earth" soil profile is divided into eight different fractios: 390 microns. Ag, As, Ba, Be, Bi, Cd, Co, Cr, Cu, Ga. Ge, Hg, In, La, Li, Mo, Mn, Ni, Pb, Rb, Sb, Sn, Sr, Th, Tl, V, W, Y, and Zr, are determined by spectrography in each fraction of the two horizons studied. The relation between trace-elements contents asnd the mineralogical composition of the fractions is established when it is possible. The results show the contribution to the total of the soil of every fraction for each of the elements studied.Peer reviewe

Analytical determinations in soils standardization of methods. (I) pH organic matter and nitrogen

21 páginas, 8 tablas.-- Los autores forman "La Comisión de Métodos Analíticos del Instituto Nacional de Edafología y Agrobiología José M.ª Albareda.[ES] La comisión de métodos analíticos del Instituto Nacional de Edafología y Agrobiologia "José M.º Albareda" lleva varios años trabajando en la normalización de los métodos aplicables a las determinaciones analíticas de suelos. Como parte de este trabaj, en esta primera publicación se describen los métodos normalizados para la determinación de pH, materia orgánica y nitrógeno.[EN] The analytical methods committec of the Instituto Nacional de Edafología y Agrobiología "José M.ª Albareda" is working for several years on the standardization of methods to be applied to the analytical determinations of soils. As a par: of this work, the determination of pH, organic matter and nitrogen are described in this paper.Peer reviewe

Anales de Edafología y Fisiología Vegetal Tomo 14 Número 11

Caracterización de las arcillas del braunlehm de la Guinea continental española, por losé Mª Albareda, V . Aleixandre y Mª del Carmen Sánchez Calvo.--Aplicaciones analíticas espectrofotométricas del sistema Cr2 O7-2Cr+++. III. Determinación del contenido en materia orgánica de los suelos de la Vega de Granada, por F. Capitán García y M. Lachica Garrido.--Estudios de .competencia. I. Variaciones del .contenido proteico de la avena elevada y de la alfalfa en cultivo asociado, por Gaspar González y Erundino Alonso.--La eficacia de la actividad de la fauna del suelo desde el punto de vista edafológko, por W. L. KubienaPeer reviewe