Exploiting of Green Synthesized Metal Oxide Nanoparticles in the Potentiometric Determination of Metformin Hydrochloride in Pharmaceutical Products

Table 1

Qualitative determination for preliminary phytochemicals in the millet extract.

Phytochemicals	Chemical test	Positive indication sign
Flavonoids	Sodium hydroxide few drops and few drops of hydrochloric acid	Deep yellow color was removed by few drops of hydrochloric acid
Alkaloids	Dragendorff reagent	Orange or red precipitate
Tannins	Ferric chloride (1%)	Blackish blue color
Saponin	Foam test	Foam more than 1 cm
Terpenoids	Salkowski’s test	Reddish-brown precipitate
Phenols	Bromine water	White precipitate
Proteins	Biuret test, copper sulfate solution
Carbohydrates	Tollen’s reagent	Silver mirror