Penentuan Glukosa Kolorimetrik

Mengukur analog glukosa darah menggunakan metode DNS

Colorimetry Intermediate (High School) 60 menit ~$10,00

Tujuan

Tentukan konsentrasi glukosa menggunakan metode kolorimetri asam dinitrosalisilat (DNS) dan pahami kimia gula pereduksi.

Latar Belakang

The DNS method is a classic colorimetric assay for reducing sugars. 3,5-dinitrosalicylic acid (yellow) is reduced by the free aldehyde group of glucose to 3-amino-5-nitrosalicylic acid (orange-red). The color change occurs upon heating, and the intensity at 540 nm is proportional to the reducing sugar concentration. This method is widely used in food science and fermentation monitoring.

Peringatan Keselamatan

  • DNS reagent contains NaOH — corrosive to skin
  • Boiling water bath — handle tubes with tongs
  • Cool tubes before opening to prevent splattering
  • DNS reagent stains skin yellow

APD yang Diperlukan

goggles gloves lab_coat

Bahan

  • DNS reagent (100 mL)
    1% DNS in NaOH with sodium potassium tartrate
  • Glucose stock solution (100 mL)
    10 mg/mL in water
  • Unknown sugar solution (20 mL)
  • Distilled water (200 mL)

Peralatan

Spectrophotometer or colorimeter Cuvettes Boiling water bath Test tubes (10) with caps Pipettes (1 mL, 5 mL) Ice bath Timer

Prosedur

1

Prepare glucose standards: 0, 1, 2, 4, 6, 8, 10 mg/mL by diluting the stock solution.

10 menit
2

Add 1 mL of each standard and the unknown to labeled test tubes. Add 1 mL of DNS reagent to each tube.

5 menit DNS contains NaOH
3

Place all tubes in a boiling water bath for exactly 5 minutes. The color changes from yellow to orange-red.

5 menit Use tongs for hot tubes
4

Transfer tubes immediately to an ice bath to stop the reaction. Cool for 2 minutes.

2 menit
5

Add 8 mL of distilled water to each tube and mix well.

5 menit
6

Measure absorbance at 540 nm. Zero with the blank (0 mg/mL glucose).

15 menit
7

Plot the calibration curve and determine the glucose concentration of the unknown.

18 menit

Hasil yang Diharapkan

A linear calibration curve from 1–10 mg/mL glucose. The color intensifies from pale yellow (blank) to deep orange-red (10 mg/mL). Non-reducing sugars like sucrose give no color change.

Pembersihan

Neutralize DNS waste with dilute HCl before disposal. Clean test tubes immediately as dried DNS residue is difficult to remove.

Detail

Kategori
Colorimetry
Tingkat Kesulitan
Intermediate (High School)
Durasi
60 menit
Perkiraan Biaya
$10,00
Langkah
7
Bahan
4

Eksperimen Lainnya

Analisis Pewarna Makanan dengan Spektrofotometri 60 min Analisis Spektrofotometrik Campuran 75 min Penentuan Aspirin Spektrofotometrik 75 min Penentuan Besi dalam Air 75 min Penentuan Fosfat Kolorimetrik 90 min Uji Protein Kolorimetrik (Metode Bradford) 60 min Verifikasi Hukum Beer-Lambert 60 min

Frequently Asked Questions

What is the objective of Penentuan Glukosa Kolorimetrik?
Tentukan konsentrasi glukosa menggunakan metode kolorimetri asam dinitrosalisilat (DNS) dan pahami kimia gula pereduksi.
How difficult is Penentuan Glukosa Kolorimetrik?
This experiment is rated as Intermediate (High School). It takes approximately 60 minutes to complete.
What safety precautions are needed for Penentuan Glukosa Kolorimetrik?
Key safety precautions include: DNS reagent contains NaOH — corrosive to skin; Boiling water bath — handle tubes with tongs; Cool tubes before opening to prevent splattering.
What materials are needed for Penentuan Glukosa Kolorimetrik?
The main materials required are: DNS reagent, Glucose stock solution, Unknown sugar solution, Distilled water.
What results should I expect from Penentuan Glukosa Kolorimetrik?
A linear calibration curve from 1–10 mg/mL glucose. The color intensifies from pale yellow (blank) to deep orange-red (10 mg/mL). Non-reducing sugars like sucrose give no color change.