Iyo 20-60ml Epa yekuchengetedza vial vial mudziyo wakasarudzika wakagadzirirwa kuchengetedza uye kuchengetedza kwekuongorora kwesangano (VOA) samples mu laboratori. Iyo ine huwandu hwekugona kwe20-60ml, kupa iyo yakakwana nzvimbo yekuenzanisa yekuunganidza uye kuchengetedza. Iyo vial yakagadzirwa nemhando yepamusoro, yemakemikari inodzivirira zvinhu kuti uve nechokwadi chekutendeka mumuenzaniso panguva yekuchengetedza kwenguva refu.