Subsampling errors in active chlorophyll a determination in water samples

This paper investigated three chlorophyll-a analysis methods in water sample. The UV-VIS spectrophotometry method followed SL88-2012 standard procedure, the results showed the detection limit of chlorophyll-a was 0.22 μg/L, with the lower detection limit of 1.0 μg/L. The detection range of the vivo chlorophyll-a fluorescence method was 0.1-300μg/L, the ratios of different algae matched that prepared in water samples. The detection limits and quantification limits for HPLC by using UVD and FLD were respectively 0.013 and 0.004 μg/L, 0.040 and 0.013μg/L. FLD was more sensitive than UVD for chlorophyll-a analysis, and the recovery of standard addition was in the range of 90.2% to 103.9% with UVD and FLD. Given the different pretreatment procedures of the sample, equipment conditions, correction and precision, vivo chlorophyll-a fluorescence method was the best on-site monitoring and the emergency monitoring method. Spectrophotometer was suitable for routine laboratory determination of chlorophyll-a, especially for bulk water samples. HPLC method had high precision and sensitivity, so this method applied to the determination of exact requirements, microanalysis and pigment separation.

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Carbon biomass, carbon-to-chlorophyll a ratios and growth rates of phytoplankton in Jiaozhou Bay, China

10.5194/egusphere-egu21-9685 ◽

2021 ◽

Author(s):

Shujin Guo ◽

Xiaoxia Sun

Keyword(s):

Chlorophyll A ◽

Growth Rates ◽

Water Samples ◽

Jiaozhou Bay ◽

Phytoplankton Growth ◽

Biomass Carbon ◽

Carbon Biomass ◽

Four Seasons ◽

Carbon Based ◽

Phytoplankton Cells

Carbon biomass, carbon-to-chlorophyll a ratio (C:Chl a) values and growth rates of phytoplankton cells were studied during four seasonal cruises in 2017 and 2018 in Jiaozhou Bay, China. Water samples were collected from twelve stations, and phytoplankton carbon biomass (phyto-C) was estimated from microscope-measured cell volumes. Phyto-C ranged from 5.05 to 78.52 &#956;g C/L (mean 28.80 &#956;g C/L) in the bay, and it constituted a mean of 38.16% of the total particulate organic carbon in the bay. High phyto-C values always appeared in the northern or northeastern bay. Diatom carbon was predominant during all four cruises. Dinoflagellate carbon contributed much less (<30%) to the total phyto-C, and high values always appeared in the outer bay. The C:Chl a of phytoplankton cells varied from 11.50 to 61.45 (mean 31.66), and high values appeared in the outer bay during all four seasons. The phyto-C was also used to calculate the intrinsic growth rates of phytoplankton cells in the bay, and phytoplankton growth rates ranged from 0.56 to 1.96 day-1; the rate was highest in summer (mean 1.79 day-1), followed by that in fall (mean 1.24 day-1) and spring (mean 1.17 day-1), and the rate was lowest in winter (mean 0.77 day-1). Temperature and silicate concentration were found to be the determining factors of phytoplankton growth rates in the bay. To our knowledge, this study is the first report on phytoplankton carbon biomass and C:Chl a based on water samples in Jiaozhou Bay, and it will provide useful information for studies on carbon-based food web calculations and carbon-based ecosystem models in the bay.

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Water quality. Guidance on the use of in vivo absorption techniques for the estimation of chlorophyll-a concentration in marine and fresh water samples

10.3403/30233320u ◽

2015 ◽

Keyword(s):

Water Quality ◽

Chlorophyll A ◽

Fresh Water ◽

Water Samples ◽

Chlorophyll A Concentration ◽

In Vivo Absorption

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Limnological features Diwanyia River, Iraq

Baghdad Science Journal ◽

10.21123/bsj.1.1.119-124 ◽

2004 ◽

Vol 1 (1) ◽

pp. 119-124

Author(s):

Baghdad Science Journal

Keyword(s):

Carbon Dioxide ◽

Dissolved Oxygen ◽

Chlorophyll A ◽

Fresh Water ◽

Water Samples ◽

Total Hardness ◽

Dissolved Carbon ◽

Dissolved Carbon Dioxide ◽

Calcium Magnesium ◽

Nitrite Nitrate

Monthly water samples from three stations in Diwanya river at Diwanyia city were collected during December 1999 to June 2000. Variables from each stations were determined including ; temperature, pH ,dissolved oxygen, dissolved carbon dioxide , alkalinity ,total hardness, calcium ,magnesium , phosphate, nitrite, nitrate, chlorophyll-a , and total number of phytoplankton .The river considered as fresh water , alkaline ,very hard .The parameters recorded at different values from up and down stream.

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Water quality. Guidance on the use of in vivo absorption techniques for the estimation of chlorophyll-a concentration in marine and fresh water samples

10.3403/30233320 ◽

2012 ◽

Keyword(s):

Water Quality ◽

Chlorophyll A ◽

Fresh Water ◽

Water Samples ◽

Chlorophyll A Concentration ◽

In Vivo Absorption

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Pollutant Identification by Selected Area Electron Diffraction

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100052675 ◽

1974 ◽

Vol 32 ◽

pp. 532-533

Author(s):

R. E. Ferrell ◽

G. G. Paulson ◽

C. W. Walker

Keyword(s):

Thermal Treatment ◽

Electron Diffraction ◽

Sample Preparation ◽

Crystal Structures ◽

Water Samples ◽

Environmental Samples ◽

Short Review ◽

Selected Area Electron Diffraction ◽

Multiple Component

Selected area electron diffraction (SAD) has been used successfully to determine crystal structures, identify traces of minerals in rocks, and characterize the phases formed during thermal treatment of micron-sized particles. There is an increased interest in the method because it has the potential capability of identifying micron-sized pollutants in air and water samples. This paper is a short review of the theory behind SAD and a discussion of the sample preparation employed for the analysis of multiple component environmental samples.

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Enumeration and Identification of Asbestos Fibres in Water

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010005264x ◽

1974 ◽

Vol 32 ◽

pp. 526-527 ◽

Cited By ~ 1

Author(s):

O. Mudroch ◽

J. R. Kramer

Keyword(s):

Water Supply ◽

Water Samples ◽

Drainage Basin ◽

Lake Superior ◽

Research Work ◽

List Type ◽

The West ◽

Asbestos Fibre ◽

Amphibole Asbestos

Approximately 60,000 tons per day of waste from taconite mining, tailing, are added to the west arm of Lake Superior at Silver Bay. Tailings contain nearly the same amount of quartz and amphibole asbestos, cummingtonite and actinolite in fibrous form. Cummingtonite fibres from 0.01μm in length have been found in the water supply for Minnesota municipalities.The purpose of the research work was to develop a method for asbestos fibre counts and identification in water and apply it for the enumeration of fibres in water samples collected(a) at various stations in Lake Superior at two depth: lm and at the bottom.(b) from various rivers in Lake Superior Drainage Basin.

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High-Resolution electron crystallography of the light-harvesting chlorophyll-a/b protein complex from chloroplast membranes

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100181816 ◽

1990 ◽

Vol 48 (1) ◽

pp. 610-610

Author(s):

Werner Kühlbrandt ◽

Da Neng Wang ◽

K.H. Downing

Keyword(s):

High Resolution ◽

Electron Diffraction ◽

Chlorophyll A ◽

Protein Complex ◽

Structural Integrity ◽

Light Harvesting ◽

Lhc Ii ◽

Diffraction Patterns ◽

Difference Fourier ◽

2D Crystals

The light-harvesting chlorophyll-a/b protein complex (LHC-II) is the most abundant membrane protein in the chloroplasts of green plants where it functions as a molecular antenna of solar energy for photosynthesis. We have grown two-dimensional (2d) crystals of the purified, detergent-solubilized LHC-II . The crystals which measured 5 to 10 μm in diameter were stabilized for electron microscopy by washing with a 0.5% solution of tannin. Electron diffraction patterns of untilted 2d crystals cooled to 130 K showed sharp spots to 3.1 Å resolution. Spot-scan images of 2d crystals were recorded at 160 K with the Berkeley microscope . Images of untilted crystals were processed, using the unbending procedure by Henderson et al . A projection map of the complex at 3.7Å resolution was generated from electron diffraction amplitudes and high-resolution phases obtained by image processing .A difference Fourier analysis with the same image phases and electron diffraction amplitudes recorded of frozen, hydrated specimens showed no significant differences in the 3.7Å projection map. Our tannin treatment therefore does not affect the structural integrity of the complex.

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