METHOD FOR DETERMINING THE CONCENTRATION OF PHYTOPLANKTON PHOTOPIGMENTS, DISSOLVED ORGANIC MATTER AND THE SIZE COMPOSITION OF THE SUSPENSION IN SEAWATER IN SITU Russian patent published in 2022 - IPC G01N21/64 

FIELD: microbiology.

SUBSTANCE: invention is aimed to determine the concentration of phytoplankton photopigments, dissolved organic matter and the size composition of the suspension in seawater in situ. The essence of the invention lies in the fact that using LEDs, fluorescence is excited at different wavelengths in the measuring volume of water, the intensity and intensity of the exciting radiation are controlled, and the fluorescence signal is recorded by a photoelectronic multiplier (PM) using several different light filters, the method differs in that from the device housing from two different LEDs along two optical axes into seawater, namely into a measuring volume with specified geometric dimensions, collimated beams of exciting light with a given intensity and duration and different wavelengths are sent at an angle of 90° to the photodetector lens of the PM, which, reaching two identical triple prisms placed on these optical axes, are returned by them through the measuring volume along the same optical axes to the body of the device, where the exciting light is turned off to exclude parasitic illumination, and fluorescence light and Raman scattering light caused by exciting light from the measuring volume along the third optical axis, which passes through the measuring volume and is located at an angle of 90° to both of the first two optical axes indicated, is directed by a third triple prism, which is placed on this optical axis and is identical to the first two triple prisms indicated, into the device housing on the PM through alternately replaceable light filters mounted on a rotary disk, and the moment of light passage through light filters, it is synchronized with the emission of different wavelengths of exciting light by LEDs in such a way that the combination of the emitted light, exciting fluorescence and Raman scattering of light in water, and light filters corresponded to the fluorescence light of phytoplankton, dissolved organic matter and Raman scattering of light, then the signals from the PM are converted into voltages, their analog-to-digital conversion is carried out, they are recorded digitally on a memory card and using calibration coefficients, the concentration values of phytoplankton photopigments, dissolved organic matter substances and the dimensional composition of the suspension in the measuring volume of seawater are determined.

EFFECT: providing the possibility of simultaneous in situ measurement of several bio-optical parameters of the studied water area, obtained in the spectral range from 350 nm to 700 nm, such as the concentration of phytoplankton photopigments; concentration of dissolved organic matter; the size composition of the suspension.

3 cl, 1 dwg