DD242686A1 - ANALYSIS METHOD FOR THE QUANTITATIVE RECORDING OF PHYSIOLOGICALLY ACTIVE PHYTOPLANKTON - Google Patents

Abstract

The invention, analytical method for the quantitative detection of physiologically active phytoplankton, serves to detect chlorophyll-containing phytoplankton by means of fluorescence optical methods quickly, easily and safely quantitatively. First, the determination of the fluorescence intensity determines the chlorophyll a content, which is related to the total photosynthetic biomass. Secondly, the use of DCMU to increase fluorescence intensity makes it possible to assess bioactivity. The determination of these parameters and the knowledge of some relationships with other physiological as well as physicochemical laws make it possible to evaluate the degree of trophy of the waters and to predict quantitatively possible changes.

Description

Since the plankton sample is of unknown composition and interfering factors can influence the intensity of the measuring signals, the following test should be carried out:

1. The plankton sample is bleached with a drop of a suitable bleaching agent and the possibly existing fluorescence residual signal determined. The thus measured intensity residual amount F ₃ arises from the scattering of the faded plankton and the tripton.

2. From the same initial batch, a certain volume is freed from the plankton and tripton by membrane filters. The filtrate may still contain free pigments and other solutes that could produce fluorescence. This amount of intensity F _L determined by the sample is of interest for the assessment of the water quality.

The three determined fluorescence intensities can now be used for quantification taking into account the dilution ratio.

The correction of the fluorescence total signal F _G takes place according to the relationship:

F _K = F _G -F ₅ -F ₁ .

Here F _K is the corrected fluorescence signal.

The fluorescence can be calibrated against chlorophyll-a content taking into account the nature of the majority of the existing plankton.

In detail, could

1. the dead fluorescence

2. the variable fluorescence in steady state be used for this.

According to investigations by STRASKRABA, DESORTOVA, FOTT (1979) and determinations of the chlorophyll-a content in the Havel region of the GDR, the degree of trophism corresponds to approximately the following chlorophyll a concentrations of the plankton in the case of large fluctuation ranges.

Hypertrophic Sees: 150mg / m ³ Eutrophic Sees: 5-150mg / m ³

Mesotrophic lakes: 1-20 mg / m ³

Oligotrophic lakes: 5 mg / m ³

To determine the photosynthetic activity of the phytoplankton sample:

The determination of the photosynthetic activity takes place by the formation of the difference of the fluorescence values in the quasi-steady state before and after the DCMU application or the difference of the measured values of the fluorescence in the quasi-steady state and the dead fluorescence without DCMU treatment. ~.

embodiments

1st embodiment

The chlorophyll-a content of a phytoplankton sample is to be determined. It becomes the fluorescence induction curve after 3 min.

Dark time of this plankton sample with a turbidity value of 0.05 at 750 nm recorded by means of a fluorescence measuring. Thereafter, a DCMU-application is carried out (10 ^"5 M) and, after a waiting period of five minutes, the registration of the increased Fluoreszehzintensität. Another Phytoplankton is bleached with a drop of Eau de Javelle. The intensity balance Fs is determined.

Ten milliliters of the starting sample are filtered and the amount of fluorescence of the plankton and triptone-free filtrate is measured.

The magnitudes of the measured intensities are for

Fg ⁼ 55,

Fs = 4, \

F _L = 10 relative units.

For Fq, the intensity of the untreated sample was chosen to be quasi-steady state. After the relationship

Fk = F _g F ₅ -F. ₁ ,

the value of 41 relative units is given for F _K. ,

The correction of the fluorescence intensity increased by DCMU, which is not taken into consideration here, is carried out analogously, since only the chlorophyll-a content is to be determined.

After the equation

Cchi = K · F _K

with a previously determined K value of 0.548 mg / m ³ results in a chlorophyll-a concentration of 22.5 mg / m ³ .

A classification according to the degree of trophy shows that the values determined could be a transition from the meso to the eutrophic stage of the lake.

Claims (3)

claims: 1. An analytical method for the quantitative detection of physiologically active phytoplankton, characterized in that also fluorescence optical methods chlorophyll-containing plankton in the natural and artificial .Waters with different levels of pollution quickly, easily and safely quantitatively by determining the chlorophyll aGehaltes proportional corrected fluorescence signal and by DCMU Application detected by Q-reduction photosynthetic activity is detected by fluorescence measurement. 2. The method according to item 1, characterized in that takes place with a simple or if necessary multiple correction of fluorescence by fading the plankton and triptone and the separation of the particles of an untreated sample by filtration and measurement of the fluorescence of the dissolved components in the sample. 3. The method according to item 1 and 2, characterized in that the fluorescence measurements can be performed with suitable devices of different types to the simplest solutions both in the laboratory and in the field. Field of application of the invention Environmental protection, water management, drinking water control Characteristic of the known technical solutions A similar method is the chlorophyll determination by spectrometric analysis, in which the pigment of a prescribed collected and concentrated plankton sample is extracted with a suitable extractant and photometry at the appropriate wavelength. This requires numerous operations that can only be done in the laboratory. Chlorophyll solutions are highly sensitive to light, which makes it necessary to work up the extracts as quickly as possible in low-light conditions. The method described permits statements on the biomass content of phytoplankton samples, taking into account the specific nature of the ratio between pigment content and cell volume. There is no possibility for bioactivity determination. The indication of the biological activity of effectors is carried out according to the patent DD G 01 N 33/52 214455 by means of autotrophically cultured cell suspensions of green algae by fluorometric analyzes. In this "selection process for the photosynthesis by means of analyzes of prompt chlorophyll-a fluorescence" is done so that each fluorescence except the control a defined amount of chemical compounds applied at constant intervals before the measurement in the dissolved state and ensures equal pretreatment of all samples In carrying out each individual measurement, the effect on the state of the cell or of the subcellular particle is detected as a change in the fluorescence intensity The disclosure DE 2938056 A1 "Device for the fluorometric evaluation of samples" presents a simple device which permits fluorometric determination of chlorophyll. Object of the invention The aim of the invention is to propose a method which, by means of fluorescence-optical methods, rapidly, simply and reliably quantitates chlorophyll-containing phytoplankton in a physiologically active state in natural and artificial waters with different degrees of contamination. The determination of the intensity of chlorophyll a fluorescence and the knowledge of some relationships with other physiological as well as physicochemical Ti laws make it possible to evaluate the degree of trophic status of waters and possibly changes quantitatively on the chlorophyll a content of the total photosynthetically active phytoplankton in freshwater or seawater samples as well as the controlled DCMU sensitivity serve as parameters for the quantitative characterization of the existing photosynthetic biomass and their photosynthetic activity. Explanation of the essence of the invention The invention has for its object to detect chlorophyll-containing phytoplankton by means of fluorescence optical methods quickly, easily and safely quantitatively. First, the determination of the fluorescence intensity determines the chlorophyll content, which is related to the total photosynthetic biomass. Secondly, the use of DCMU to increase the fluorescence intensity makes it possible to make a statement about the bioactivity. In the "analytical method for the quantitative detection of phytoplankton", the procedure is such that the required sample volume is adjusted to a slight turbidity at 750 nm, depending on the trophic level of the sampling location and the sampling depth for the fluorescence measurement, depending on the fluorescence measuring device used As a rule, only dilution must be carried out Before the measurement of the fluorescence, the samples must be subjected to a time-defined dark phase during which time plankton sedimentation is to be avoided, after which the fluorescence induction curve of the sample is recorded an application of DCMU or another suitable substance in order to achieve a fluorescence increase corresponding to the bioactivity After the application of the active substance, an exposure which simultaneously serves to transport DCMU to the site of action is to be carried out n. The measured value must first be recorded after some time in order to also detect species with different permeation time constants. If no fluorescence increase can be detected with DCMU and thus the assumption of DCMU resistance is obvious, the increase should be made by dark reduction of the electron transport carrier Q with sodium dithionite.