Author
Bruce W. Lium
Bio: Bruce W. Lium is an academic researcher from United States Geological Survey. The author has contributed to research in topics: Chlorophyll & Dimethyl sulfoxide. The author has an hindex of 1, co-authored 2 publications receiving 477 citations.
Papers
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TL;DR: Dimethyl sulfoxide (DMSO) and 90% acetone extracted equal amounts of chlorophyll from diatoms and blue-green algae, but DMSO was superior to 90%acetone for all green algae tested giving 2-60 times more chlorophyLL depending on the species as discussed by the authors.
Abstract: Dimethyl sulfoxide (DMSO) and 90% acetone extracted equal amounts of chlorophyll from diatoms and blue-green algae, but DMSO was superior to 90% acetone for all green algae tested giving 2–60 times more chlorophyll depending on the species. The absorbance spectra of pure chlorophyll a (and b) from 600 nm to 750 nm were identical whether dissolved in 90% acetone or a mixture of DMSO and 90% acetone (1:1 v/v). Thus, several equations for estimating chlorophyll concentration based on extinction in 90% acetone are applicable with this solvent.
507 citations
TL;DR: In this article, nine samples, each with different kinds and numbers of algae, were filtered at five pressures from 5 to 75 pounds per square inch and the amounts of chlorophylls a and b were measured.
Abstract: Nine samples, each with different kinds and numbers of algae, were filtered at five pressures from 5 to 75 pounds per square inch and the amounts of chlorophylls a and b were measured. Pressures in the range tested had no effect on the measured amounts.
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TL;DR: A simple, rapid method requiring few manipulations for the extraction of chlorophylls from fragmented leaf tissue of angiosperms and gymnosperms is compared with the widely used acetone method, which makes use of incubation at 65 °C of leaf tissue immersed in dimethyl sulphoxide.
Abstract: A simple, rapid method requiring few manipulations for the extraction of chlorophylls from fragmented leaf tissue of angiosperms and gymnosperms is compared with the widely used acetone method. Unlike the acetone method where grinding and subsequent centrifugation are essential, this method makes use of incubation at 65 °C of leaf tissue immersed in dimethyl sulphoxide. The new method was found to be as efficient as acetone for chlorophyll extraction and superior in terms of chlorophyll stability.
2,810 citations
TL;DR: The efficiency of pigment extraction forms the crux of the spectrophotometric analysis of chlorophyll a and the alcoholic solvents, methanol and ethanol, proved to be superior to acetone and acetone with DMSO.
Abstract: The efficiency of pigment extraction forms the crux of the spectrophotometric analysis of chlorophyll a. The alcoholic solvents, methanol and ethanol, proved to be superior to acetone and acetone with DMSO. Homogenisation and sonication did not improve the extraction in the alcoholic solvents. Boiling at 100°C had an adverse effect whereas complete extraction of the pigments was obtained at the solvents boiling point and allowing the samples to stand for 24 h in the dark.
833 citations
TL;DR: In this article, the use of DMSO for the extraction and determination of chlorophylls a and b in lichens and higher plants was reevaluated, and the problem of degradation resulting from the presence of acidic lichen substances was specifically addressed.
824 citations
TL;DR: The SPAD-502 has been shown to be a good tool to diagnose the integrity of the photosynthetic system in coffee leaves, and can thus help in the advanced interpretations of the photochemical process of these plants.
498 citations
TL;DR: It was found that, in general, when phytoplankton abundance increases, larger sizeclasses are added incrementally to a background of smaller cells, such as pigment packaging and concentration of accessory pigments.
Abstract: Size-fractionated chlorophyll concentration and phytoplankton absorption spectra were compared for a wide variety of natural communities. We found that, in general, when phytoplankton abundance increases, larger sizeclasses are added incrementally to a background of smaller cells. Natural phytoplankton communities from surface waters were explicitly characterized according to their dominant cell size and taxonomic group, and the relationships between this classification and the spectral shape of the phytoplankton absorption coefficient for the whole assemblage was described. By specifying the cell size of the dominant organism (pico-, ultra-, nano-, or microplankton), more than 80% of the variability in spectral shape of the phytoplankton absorption coefficient from 400 to 700 nm could be explained. This is a result of the strong covariation of the size of dominant organisms and several factors controlling the spectral shape of the phytoplankton absorption coefficient, such as pigment packaging and concentration of accessory pigments. Consequently, the shapes of phytoplankton absorption spectra can be reproduced using a spectral mixing model, where two spectra, representing the normalized phytoplankton absorption coefficients for the smallest and the largest cells found in our data set, are combined additively, using a single parameter to specify the complementary contribution of each. The differences between reproduced and measured spectra contain taxonomic and physiological information. This parameterization provides a simple tool for extracting ecological information from optical measurements. It can also be used in sensitivity analyses to describe the influence of the dominant cell size of phytoplankton on optical properties of surface waters. Changes in phytoplankton species composition are a central feature of marine ecosystem dynamics. Description and prediction of these changes are important goals to many fields in oceanography. In recent years, great effort has been made to understand how changes in phytoplankton species composition can affect optical properties of surface waters (e.g., Morel 1997; Kahru and Mitchell 1998; Stuart et al. 1998; Stramski et al. 2001). A major application of these results is the use of in situ optical instruments or remote sensing to observe variability of phytoplankton continuously or synoptically. This is a complicated topic because phytoplankton communities include species differing in size, shape, external and internal structures, and pigment composition. All these characteristics influence their interaction with the light field to some degree, so many factors must be considered to completely describe the optical properties of different communities of phytoplankton. A central goal is 1
445 citations