Glukozun Kolorimetrik Tayini

DNS yöntemiyle kan glukozu analogunu ölçme

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

Hedef

Dinitrosalisilik asit (DNS) kolorimetrik yöntemiyle glukoz konsantrasyonunu belirlemek ve indirgen şeker kimyasını anlamak.

Arka Plan

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.

Güvenlik Uyarıları

  • 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

Gerekli KKD

goggles gloves lab_coat

Malzemeler

  • 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)

Ekipman

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

Prosedür

1

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

10 dak
2

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

5 dak 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 dak Use tongs for hot tubes
4

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

2 dak
5

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

5 dak
6

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

15 dak
7

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

18 dak

Beklenen Sonuçlar

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.

Temizlik

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

Ayrıntılar

Kategori
Colorimetry
Zorluk
Intermediate (High School)
Süre
60 dak
Tahmini Maliyet
$10,00
Adımlar
7
Malzemeler
4

Daha Fazla Deney

Aspirinin Spektrofotometrik Tayini 75 min Beer-Lambert Yasasının Doğrulanması 60 min Fosfat Kolorimetrik Tayini 90 min Karışımın Spektrofotometrik Analizi 75 min Kolorimetrik Protein Analizi (Bradford Yöntemi) 60 min Spektrofotometreyle Gıda Boyası Analizi 60 min Sudaki Demir Tayini 75 min

Frequently Asked Questions

What is the objective of Glukozun Kolorimetrik Tayini?
Dinitrosalisilik asit (DNS) kolorimetrik yöntemiyle glukoz konsantrasyonunu belirlemek ve indirgen şeker kimyasını anlamak.
How difficult is Glukozun Kolorimetrik Tayini?
This experiment is rated as Intermediate (High School). It takes approximately 60 minutes to complete.
What safety precautions are needed for Glukozun Kolorimetrik Tayini?
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 Glukozun Kolorimetrik Tayini?
The main materials required are: DNS reagent, Glucose stock solution, Unknown sugar solution, Distilled water.
What results should I expect from Glukozun Kolorimetrik Tayini?
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.