METHOD FOR BIOTESTING TOXICITY OF WATER AND AQUEOUS SOLUTIONS

摘要

The invention relates to biophysical methods of determining toxicity of water and aqueous solutions and can be applied for operative biotesting toxicity of natural and waste waters and also for establishing danger classes of different wastes in using micro water seeds and other vegetable organisms as a plant object. The toxic effect on the plant subject is evaluated based on registering the changes of delayed fluorescence intensity of chlorophyll containing therein. The technical effect provides high accuracy and sensitivity of the method for determining toxicity of water and aqueous solutions by providing new conditions of the changes of delayed fluorescence intensity of chlorophyll in vegetable objects. The technical result is characterised by that the method of biophysical determination toxicity of water and aqueous solutions involves exposing the analysed sample of a plant object to intermittent light of high intensity of 100-250 W/m from blue light-emitting diodes with luminous excitation of said sample and detection of after-glow in the red spectral region using a photodetector between light pulses passing through a red light filter, wherein by cutting duration of light periods of luminous excitation while simultaneously increasing dark intervals in between, conditions are created for low light exposure, and by increasing the ratio of duration of light periods to dark periods, conditions are created for high light exposure; intensity of delayed fluorescence of the analysed sample is measured in high light exposure mode at the beginning of each damping curve; intensity in low light exposure mode is measured at the end of each damping curve, and toxicity is determined from their ratio.