Eine neue Apparatur zur Druckveraschung von biologischem Material

Schramel, P.; Wolf, A.P.; Seif, R.; Klose, Birgit

doi:10.1007/bf00469765

Cited by 95 publications

(28 citation statements)

References 1 publication

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“…After digestion of the organic material using a pressure ashing technique with nitric acid (26), Ca, K, Mg, P, and S analyses were preformed by inductively coupled plasma emis- was due to an increase in both transmittance and reflectance 15 * (Fig. 2).…”

Section: Methodsmentioning

confidence: 99%

Photosynthesis and Chlorophyll Fluorescence Characteristics in Relationship to Changes in Pigment and Element Composition of Leaves of Platanus occidentalis L. during Autumnal Leaf Senescence

Adams

Winter²,

Schreiber³

et al. 1990

Plant Physiol.

113

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The loss of chlorophyll and total leaf nitrogen during autumnal senescence of leaves from the deciduous tree Platanus occidentalis L. was accompanied by a marked decline in the photosynthetic capacity of 02 evolution on a leaf area basis. When expressed on a chlorophyll basis, however, the capacity for lightand C02-saturated O2 evolution did not decline, but rather increased as leaf chlorophyll content decreased. The photon yield of 02 evolution in white light (400-700 nanometers) declined markedly with decreases in leaf chlorophyll content below 150 milligrams of chlorophyll per square meter on both an incident and an absorbed basis, due largely to the absorption of light by nonphotosynthetic pigments which were not degraded as rapidly as the chlorophylls. Photon yields measured in, and corrected for the absorptance of, red light (630-700 nanometers) exhibited little change with the loss of chlorophyll. Furthermore, PSII photochemical efficiency, as determined from chlorophyll fluorescence, remained high, and the chlorophyll a/b ratio exhibited no decline except in leaves with extremely low chlorophyll contents. These data indicate that the efficiency for photochemical energy conversion of the remaining functional components was maintained at a high level during the natural course of autumnal senescence, and are consistent with previous studies which have characterized leaf senescence as being a controlled process. The loss of chlorophyll during senescence was also accompanied by a decline in fluorescence emanating from PSI, whereas there was little change in PSII fluorescence (measured at 77 Kelvin), presumably due to decreased reabsorption of PSII fluorescence by chlorophyll. Nitrogen was the only element examined to exhibit a decline with senescence on a dry weight basis. However, on a leaf area basis, all elements (C, Ca, K, Mg, N, P, S) declined in senescent leaves, although the contents of sulfur and calcium, which are not easily retranslocated, decreased to the smallest extent.

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Section: Methodsmentioning

confidence: 99%

Photosynthesis and Chlorophyll Fluorescence Characteristics in Relationship to Changes in Pigment and Element Composition of Leaves of Platanus occidentalis L. during Autumnal Leaf Senescence

Adams

Winter²,

Schreiber³

et al. 1990

Plant Physiol.

113

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“…Two milliliters concentrated nitric acid (grade ACS) were added to each tube. These tubes were subsequently capped and heated to 180°C in a high-pressure digestion apparatus (Schramel et al 1980). Briefly, the digestion apparatus consisted of a custom-made aluminum block with holes to fit up to six Teflon sleeves and quartz digestion tubes and caps.…”

Section: Materials and Proceduresmentioning

confidence: 99%

Quantification of black carbon in marine systems using the benzene polycarboxylic acid method: a mechanistic and yield study

Ziolkowski

Chamberlin

Greaves

et al. 2011

Limnology & Ocean Methods

122

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Quantification of black carbon (BC), carbonaceous material of pyrogenic origin, has typically required either chemical or thermal oxidation methods for isolation from heterogeneous matrices, such as sediment or soil. The benzene polycarboxylic acid (BPCA) method involves chemical oxidation of aromatic structures, such as those in BC, into BPCAs. We revised the BPCA method with the intent to quantify BC in marine dissolved organic carbon (DOC). As part of this work, we evaluated the mechanism and yield of the method using nine polycyclic aromatic hydrocarbons (PAHs) and six BC reference materials. After 8 h of oxidation at 180°C, the average carbon yield was 26 ± 7% C and was not correlated to the molecular weight of the PAH oxidized. The majority of observed BPCAs were nitrated, which has serious implications for the quantification of BC. Smaller PAHs favor the formation of less substituted BPCAs, whereas larger PAHs, such as coronene, favor the formation of more fully substituted BPCAs. Time‐course experiments revealed variations of BPCA distributions over time, favoring less substituted BPCAs with longer oxidation times, whereas the carbon yield exhibited little variation. No decarboxylation of fully substituted mellitic acid (B6CA) was observed during time course experiments. Using the model compound anthracene, a potential internal standard, we propose a mechanism for the oxidation reaction based on time‐course experiment data. Quantification of BC in reference materials revealed that this revision of the BPCA method is significantly more efficient than previous versions and is effective for quantifying both char and soot BC.

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“…I M chloramphenicol to 50 mL of sample. To determine particulate bound substances the filters were digested using a HNO3/pressure digestion technique (Schramel et al, 1980). All vessels and the filters were preconditionated with dilute HNO3.…”

Section: Methodsmentioning

confidence: 99%

Impact of high aluminium loading on a small catchment area (thuringia slate mining area) —geochemical transformations and hydrological transport

Peiffer

Beierkuhnlein

Sandhage‐Hofmann

et al. 1997

Water Air Soil Pollut

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Abstract. A field study was performed on the effects of acid mine leachate from slate mine tailings seeping into a small river passing through the tailings. Before entering the tailings the river water has high alkalinity which neutralizes acidity upon mixing with leachate within the tailings. Downstreams of the tailings the pH of the river water ranges about pH = 8, the water contains high concentrations of sulfate (~1500 Ftmol/l) and particulate bound aluminium (~80 iLmol/l), but low concentrations of dissolved aluminium (~3 #mol/1). It is therefore assumed that AI(OH)3 colloids are precipitated during the neutralisation process and transported out of the tailings. The concentration of particulate bound almninium along the river shows a strong correlation with the concentration of sulfate, which indicates that particulate bound aluminium is conservative. It therefore seems that under dry weather conditions (under most of the sampling was performed) no chemical retention mechanism exists which confines the distribution of aluminium to a restricted part of the catchment area. In contrast, the white river sediment is rich in both aluminium and sulfate, which suggests the temporary formation of aluminium hydroxosulfate minerals. Favorable (i.e. acidic) conditions may prevail at high discharges where the acidity accumulated in the tailings is flushed into the river with its subsequent acidification.

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Eine neue Apparatur zur Druckveraschung von biologischem Material

Cited by 95 publications

References 1 publication

Photosynthesis and Chlorophyll Fluorescence Characteristics in Relationship to Changes in Pigment and Element Composition of Leaves of Platanus occidentalis L. during Autumnal Leaf Senescence

Photosynthesis and Chlorophyll Fluorescence Characteristics in Relationship to Changes in Pigment and Element Composition of Leaves of Platanus occidentalis L. during Autumnal Leaf Senescence

Quantification of black carbon in marine systems using the benzene polycarboxylic acid method: a mechanistic and yield study

Impact of high aluminium loading on a small catchment area (thuringia slate mining area) —geochemical transformations and hydrological transport

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