Uji Fitokimia

Summary

This video script outlines a phytochemical testing process conducted on plant samples from Kalimantan's Rawa Gambut forest. The experiment tests for various secondary metabolites, including alkaloids, phenols, tannins, triterpenoids, steroids, and saponins. Reagents such as Dragendorff’s, Mayer’s, and Wagner’s are used for alkaloid detection, while FeCl3 and H2SO4 confirm tannins. Positive results for phenols, tannins, triterpenoids, and saponins are observed, with alkaloids showing no presence. The procedure involves color change reactions to confirm the presence of specific compounds, concluding with a request for participants to summarize the results.

Takeaways

• 😀 The video focuses on conducting phytochemical tests on plant samples, specifically from a Kalimantan peat swamp forest.
• 😀 The first test is for alkaloids, using reagents like Dragendorff's reagent, Mayer's reagent, and Wagner's reagent to test for positive alkaloid presence.
• 😀 Positive alkaloid test results in red color for Dragendorff, yellow for Mayer's, and red-brown for Wagner. All tests came back negative for alkaloids in this sample.
• 😀 The next test is for flavonoids, which involves using concentrated HCl, 10% Pb-acetate, and magnesium powder.
• 😀 A positive flavonoid test shows a red, yellow, or orange color after adding the reagents, but in this case, the test results were negative.
• 😀 Tannin testing follows, using FeCl3, H2SO4, and gelatin. A positive result will show a blue-black color after FeCl3 is added.
• 😀 The second tannin test shows the presence of tannins when an end precipitate forms after adding gelatin and NaCl.
• 😀 A triterpenoid and steroid test is conducted using glacial acetic acid, concentrated H2SO4, and HCl. A red or purple color indicates triterpenoids, while a blue or green color indicates steroids.
• 😀 The results of the triterpenoid/steroid test were positive for triterpenoids, with the sample turning red.
• 😀 Lastly, a saponin test is performed using aquades and HCl. The formation of foam after vortexing indicates the presence of saponins.
• 😀 The video concludes by encouraging participants to document which compounds were positive and which were negative in their tests.

Q & A

What is the purpose of the phytochemical test conducted in the script?

The purpose of the phytochemical test is to identify secondary metabolites present in plants, specifically to test for alkaloids, tannins, triterpenoids, steroids, and saponins in the plant sample.

What plant sample is used for the phytochemical test in the script?

The plant sample used is a stem from a plant sourced from the peat swamp forest in Kalimantan.

How is the alkaloid test conducted in the script?

The alkaloid test is conducted by adding reagents such as Dragendorff, Mayer, and Wagner to separate test tubes with the plant extract. The test tubes are observed for color changes indicating the presence of alkaloids.

What are the color indicators for the alkaloid test in the script?

The color indicators for the alkaloid test are: Dragendorff gives a red color, Mayer produces a yellow color, and Wagner shows a reddish-brown color when positive.

What does a negative result in the alkaloid test indicate?

A negative result in the alkaloid test indicates that the plant sample does not contain alkaloids.

What reagents are used in the flavonoid test in the script?

The reagents used for the flavonoid test include concentrated hydrochloric acid (HCl), 10% lead acetate (Pb-acetate), and magnesium powder.

How is the flavonoid test performed, and what are the positive indicators?

In the flavonoid test, a plant sample is mixed with HCl and lead acetate. A yellow, red, or orange color indicates a positive result for flavonoids.

What chemicals are used in the tannin test in the script?

The chemicals used in the tannin test include FeCl3 (ferric chloride), concentrated H2SO4 (sulfuric acid), gelatin, and NaCl (sodium chloride).

What is the significance of the color changes in the tannin test?

In the tannin test, the appearance of a blue-black color after adding FeCl3 indicates the presence of tannins. The further addition of HCl and H2SO4 helps confirm the result.

How is the saponin test conducted, and what does the result indicate?

The saponin test is conducted by mixing the plant extract with distilled water and shaking it in a vortex. If foam forms, the sample contains saponins.

What is the role of HCl in the saponin test?

HCl is added in the saponin test to confirm the presence of saponins. If foam remains after the addition of HCl, it confirms the presence of saponins in the plant sample.

What does the test for triterpenoids and steroids involve?

The test for triterpenoids and steroids involves adding glacial acetic acid, concentrated sulfuric acid, and HCl to the plant extract. A blue or green color indicates steroids, while a red or purple color indicates triterpenoids.

What was the outcome of the tests conducted in the script?

The tests conducted in the script showed negative results for alkaloids, positive results for flavonoids and tannins, and positive results for saponins. The triterpenoids and steroids tests yielded a positive result for triterpenoids, indicated by a red color.