The application of dry aronia fruit, Aronia melanocarpa (Michx.) Elliott, as acid-base indicator

U učionici kemije, prirodni indikatori odlična su zamjena konvencionalnim indikatorima. Osim što su cjenovno dostupniji, mogu biti vizualno dojmljivi i omogućavaju povezivanje gradiva sa svakodnevnim životom, čime olakšavaju proces učenja. Cilj ovog rada bio je ispitati potencijal primjene suhog ploda aronije, Aronia melanocarpa (Michx.) Elliott, kao prirodnog kiselo-baznog indikatora. U tu svrhu je pripremljen niz indikatora od suhe aronije i odabranih otapala (voda, metanol, etanol, aceton). Funkcionalnost indikatora ispitivana je u periodu od četiri mjeseca, nakon čega je ispitana mogućnost recikliranja ovih indikatora. Indikatori su bili funkcionalni sve vrijeme ispitivanja, a biljni materijal korišten u pripremi indikatora pokazao je mogućnost recikliranja. Stoga se može reći da su ovakvi indikatori „zeleni“ indikatori, budući da pri njihovoj pripremi nema otpadnog materijala i budući da se mogu učinkovito reciklirati. Među ispitanim otapalima, kao vizualno najdojmljiviji pokazao se metanol, budući da je indikator pripremljen s metanolom dao lijepe i intenzivne boje.In the chemistry classroom, natural indicators are an excellent substitute for conventional indicators. Aside from price availability, they can be visually impressive and allow efficient correlation of lectures with everyday life and easier learning process. The aim of this thesis was to evaluate the potential of dry aronia fruit, Aronia melanocarpa (Michx.) Elliott, as natural acid-base indicator. For this purpose, a series of indicators containing dry aronia and selected solvents (water, methanol, ethanol, acetone) was prepared. Indicator activity was studied for four months, after which recyclability of indicators was evaluated. Indicators were functional during study period, and used plant material showed potential for recycling. Hence, we can say that in this way prepared indicators are “green” indicators, because there was no waste from their preparation and they can be successfully recycled. Among studied solvents, visually most impressive was methanol, since indicator prepared with methanol showed beautiful and intense colours