Penetapan Kadar Fenol Total [PDF]

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Penetapan Kadar Fenol Total Cara Kerja Hasil Percobaan : a. Pembuatan Kurva Baku Asam Galat (λ=752 nm) Kadar (µg/mL) 25 50 75 100 125



Absorbansi 0,224 0,484 0,707 0,720 1,039



Perhitungan regresi linier absorbansi (y) vs kadar (x) : r = 0,9736 B = 7,464.10-3 A = 0,075 Y = BX + A −3



Y =7,464. 10 X +0,075 a. Sampel (λ=752 nm) Stok sampel = 100 mg/10mL = 1000mg/100mL Sampel



Absorbansi Kadar (µg/mL)



I II III



0,959 0,915 0,926



Kadar (mg/100mL) = Kandungan Fenolik 11,8435 11,2540 11,4014



118,435 112,540 114,014



%b/b ekuivalen asam galat (EAG) = %b/b EAG mg ) 100 mL x 100 mg Kadar stok sampel( ) 100 mL



Kandungan fenolik ( =



Sampel I



mg ) 100 mL x 100 100 mg 0( ) 100 mL



11,8435 ( %b/b EAG =



%b/b EAG = 1,1844



Replikasi 1 mg ) 100 mL x 100 mg 1000( ) 100 mL



11,2540 ( %b/b EAG =



%b/b EAG = 1,1254



Replikasi 2 mg ) 100 mL x 100 mg 1000( ) 100 mL



11,4014 ( %b/b EAG =



%b/b EAG = 1,14014



1,1844 +1,1254+1,1401 3



%b/b EAG rata-rata = =



1,14997



Susut Pengeringan Macam



Sebelum Pemanasan



Setelah Pemanasan 5 jam



Bobot wadah tanpa ekstrak



Botol 1



Botol 1



Botol 2



Botol 2



(gram)



22,3504



Botol 1 (gram)



19,1478



22,3496



19,1469



Botol 2 (gram)



Bobot wadah + ekstrak



Bobot ekstrak



% bobot konstan



Bobot wadah + ekstrak



Bobot ekstrak



% bobot konstan



Sebelum pemanasan



23,357 8



1,0082



-



20,1525 1,0056



-



Pemanasan I



23,133 3



0,7837



22,26



19,9290 0,7821



22,23



Pemanasan 2



23,132 4



0,7828



0,11



19,9280 0,7811



0,13



Senyawa sisa



Senyawa hilang



Botol 1



77,64 %



22,36 %



Botol 2



77,68 %



22,32 %