ग्लूकोज का कलरिमेट्रिक निर्धारण

DNS विधि का उपयोग करके रक्त ग्लूकोज सादृश्य मापना

Colorimetry Intermediate (High School) 60 मिनट ~$10.00

उद्देश्य

डाइनाइट्रोसैलिसिलिक अम्ल (DNS) कलरिमेट्रिक विधि का उपयोग करके ग्लूकोज सांद्रता निर्धारित करें और अपचायक शर्करा रसायन को समझें।

पृष्ठभूमि

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.

सुरक्षा चेतावनियाँ

  • 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

आवश्यक PPE

goggles gloves lab_coat

सामग्री

  • 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)

उपकरण

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

प्रक्रिया

1

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

10 मिनट
2

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

5 मिनट 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 मिनट Use tongs for hot tubes
4

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

2 मिनट
5

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

5 मिनट
6

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

15 मिनट
7

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

18 मिनट

अपेक्षित परिणाम

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.

सफाई

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

विवरण

श्रेणी
Colorimetry
कठिनाई
Intermediate (High School)
अवधि
60 मिनट
अनुमानित लागत
$10.00
चरण
7
सामग्री
4

अधिक प्रयोग

एस्पिरिन का स्पेक्ट्रोफोटोमेट्रिक निर्धारण 75 min कलरिमेट्रिक प्रोटीन परख (ब्रैडफोर्ड विधि) 60 min पानी में लोहे का निर्धारण 75 min फॉस्फेट का कलरिमेट्रिक निर्धारण 90 min बीयर-लैम्बर्ट नियम का सत्यापन 60 min मिश्रण का स्पेक्ट्रोफोटोमेट्रिक विश्लेषण 75 min स्पेक्ट्रोफोटोमेट्री द्वारा खाद्य रंग विश्लेषण 60 min

Frequently Asked Questions

What is the objective of ग्लूकोज का कलरिमेट्रिक निर्धारण?
डाइनाइट्रोसैलिसिलिक अम्ल (DNS) कलरिमेट्रिक विधि का उपयोग करके ग्लूकोज सांद्रता निर्धारित करें और अपचायक शर्करा रसायन को समझें।
How difficult is ग्लूकोज का कलरिमेट्रिक निर्धारण?
This experiment is rated as Intermediate (High School). It takes approximately 60 minutes to complete.
What safety precautions are needed for ग्लूकोज का कलरिमेट्रिक निर्धारण?
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 ग्लूकोज का कलरिमेट्रिक निर्धारण?
The main materials required are: DNS reagent, Glucose stock solution, Unknown sugar solution, Distilled water.
What results should I expect from ग्लूकोज का कलरिमेट्रिक निर्धारण?
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.