| 摘要 |
FIELD: chemistry. ^ SUBSTANCE: method involves biotesting of a territory using a bioindicator in form of wild meadow steppe plants or agricultural crops, where bioindicator samples are collected during the phenological phase of their flowering in a volume of not less than 1 dm3 at plant cutting height of not less than 3 cm from the soil surface. Immediately after collection, the samples are crushed and quartered until an averaged sample is obtained in amount of not less than 100 g, a portion of which is fixed with alcohol on three surfaces. Content of selenium in the extracts is determined via spectrophotometry and the obtained average values are compared with the minimum critical content of selenium in the native mass of average cuts of wild or agricultural plants from the investigated territory, which is 20 mcg/kg for a forest zone; 30 mcg/kg for a forest-steppe zone and 50 mcg/kg for a steppe zone. The ecological status of the territory is determined from deviation from the minimum critical content of selenium. If the obtained averaged values are higher than the minimum critical content of selenium, the ecological status of the territory is considered normal. If the obtained averaged values are lower than the minimum critical content of selenium, the ecological status of the territory is considered unfavourable. ^ EFFECT: more reliable determination. ^ 3 cl, 3 ex |
