analisis vitamin 9

7/29/2019 Analisis Vitamin 9

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By: Zaidiyah S.TP, MSc


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Vitamin di definisikan sebagai senyawa

yang mempunyai BM rendah sehingga

manusia yang tergantung senyawa organik

sebagai sumber nutrient membutuhkansenyawa ini dalam jumlah yang sedikit.

Walaupun kebutuhan vitamin sedikit yang

diperoleh dari pola diet/pola makan sehari-hari ketiadaanya/kekurangannya dapat

menyebabkan kelainan fungsi sistem tubuh


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Analisis vitamin dapat dikelompokkan menjadi 3

yaitu;

1. Dengan melibatkan makhluk hidup dan

hewan.2. Dengan menggunakan mikroorganisme

seperti bakteri dan jamur

3. Analisis fisikokimia menggunakan

spectrophotometric, fluorometric,chromatographic, enzymatic, immunological,

and radiometric methods.


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Presisi dan akurasiFaktor ekonomiJumlah sample

Karakteristik sample yang akan dianalisis

Karena sifat vitamin yang sangat sensitivterhadap cahaya, oxigen, pH dan panas

maka dilakukan beberapa tindakanpencegahan untuk menghindari kerusakanvitamin tersebut selama masa analisis


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Dalam beberapa kasus analisis vitamin,

ekstraksik dilakukan pada bagian

biologis samplenya, meliputi beberapa

tindakan berikut ini yaitu; panas, asam,

alkali, pelarut dan enzim yang

digunakan. Pada umumnya prosedur

ekstraksi tergantung jenis vitaminsehingga jenis vitamin yang akan

dianalisis tetap stabil.


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Asam askorbat : Ekstraksi dingin denganasam metaphospone/asam asetat

Vitamin B1 dan B2 : dipanaskan atauautoklav dalam asam atau menggunakanenzim

Niasin : autoklav dalam enzim atau asamVitamin A, E atau D : Ekstraksi pelarut

organik, saponifikasi/penyabunan, dan

reektraksi dengan pelarut organik. Biasanyaditambahkan antioksidan agar vitaminnyatetap stabil dan menghambat prosesoksidasi


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Vitamin A cukup sensitif terhadap

uv/cahaya, udara, temperature tinggi dan

kelembaban. Oleh karena itu terdapat

beberapa langkah untuk menghindari

beberapa pengaruh seperti menghindari

suhu tinggi juga penambahan

antioksidan pada awal prosedur.


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Approximately 0.5 g of freeze-dried sweet potato root wasweighted and put into a centrifugal glass vessel.

5 ml of methanol was gift to the sample and mixed 1

minute on Vortex.

The vessel set was put on the shaker and let it shake 10minute, afterward centrifuge (Sorvall RC-5B Refrigerated

Superspeed Centrifuge serial 820) it at 3500 rpm for 15

minute long.

Then, the supernatant of the samples (clear fraction) was

transferred into 25 ml glass flask. This process was known sample extraction. This process

was repeated for 3-4 times from one sample and brought

together all supernatant of one sample into one flask

(overall 4 extractions of 1 sample/1 flask).


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Furthermore, the flask was filled up to themarked line with methanol. By usingspectrophotometer (Hewlett Packard S 453), thisextract was ready to measure the absorbance (A)

at three different wavelengths as; 470, 653 and666 nm respectively. Methanol was used as blank. Equation to determine concentration

(concentration in solution in g/ml) of

chlorophyll a (Ca) and b (Cb) as well as totalcarotenoids (Cc):Ca = (15.65 x A666)(7.34 x A653)Cb = (27.05 x A653)(11.21 x A666)


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This measurement was determined by titration withsolution 2,6-dichlorophenol-indophenol (DIP)

0.21 g of DIP-Na put in 100 ml of pure water, mixedand filtrated into 1 liter volumetric flask.

Filter was washed several times and filled up theflask to the mark. DIP solution then filled into burette.

5 ml of guava syrup were prepared and immersed in20 ml 5% metaphosphoric acid.

The solution was mixed together until 2 minutes.After homogenizing, the homogenate filled with

distilled water to a volume of 50 ml, mixed andfiltrated.

Ten ml filtrate put in Erlenmeyer flask and titratedwith 2,6 DIP until the color change to light pink


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The content of ascorbic acid can calculated according to formulabelow:Content (mg/100ml guava syrup) =(V (ml) x F1 x (100 ml/SaVo ml) x (ExtrVol/TitrVol)Which:V (Used DIP-dye solution in ml)

F1( Ascorbic acid equivalent of dye solutionexpressed as mg/ml of dye determined before with

standardized ascorbic acid solution (1 mg/1 ml) (three times)).Sa Vol (Sample volume (ml) = 5 ml)ExtrVol (Extraction volume (ml) = 50 ml)Titr Vol ( Aliquot volume (ml) used for titration = 10 ml)

The factor (F1) is the titration volume of 1 ml from 0.1% standardsolution of ascorbic acid in a mixed solution of 1 ml 5%metaphosporic acid and 9 ml distilled water. Ten of that solution istitrated using DIP.


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analisis vitamin 9

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