1. DETERMINATION OF GLUCOSE IN BLOOD STREAM
K 4-4
By: Haseeb Quadri

2. CALIBRATION CURVE Mass of Glucose (grams)
Mass of glucose is the mass you measure in the beginning of the process.
Take the exact mass by measuring it on an analytical balance.

3. Standards concentration (mg/100ml)
Mass of the sample (grams) mg
x x (volume of stock dilution)
100 ml gram
Volume of the stock dilution is 5 ml, 10 ml, 20 ml, 30 ml
--only the stock dilution changes for the four FE-standards that are made.
Sample calculation-
grams mg
x x (5 ml) =
100 ml gram

4. Absorbance The absorbance is:
(the absorbance taken (the absorbance of the
for the each standard blank)
sample)
The absorbance of the blank should not be very high

5. Calibration Curve Equation
The calibration curve equation is achieved by graphing the mg/ml (x-axis) STD. CONC. Vs Absorbance (y-axis)

6. Sample Analysis Absorbance
The absorbance is:
[the absorbance taken [the absorbance of the
for the sample] blank]
The absorbance of the blank should not be very high

7. Concentration (mg/100ml)
Take the equation of the calibration curve and calculate the concentration (x) at each absorbance of the sample.
sample calculation-
y=0.001x+0.175
for absorbance one-
0.314 = 0.001x x=139

8. Average mg/100ml Sample calc. – 139=x1+ 135=x2+ 141=x3 _
[take all the concentration at each absorbance and add them up] _
= X
[the amount of trials that are taken]
Sample calc. –
139=x1+ 135=x2+ 141=x _
= = X
3=n

9. Standard Deviation
( )^2+( )^2+( )^2 ( ) ^ (1/2) 3-1 equation- _ _ _ [ (x1 – x ) ^ 2 + (x1 – x ) ^ 2 + (x1 – x ) ^ 2 / (n-1) ] ^ (1/2) = S

10. Relative Standard Deviation (%)
_ S/ X x 100 = % rel. std. dev.

11. Question
Given the standard calibration curve equation y=0.001x and a specific absorbance at .356 of a sample and the blank being absorbed at .002, what is the concentration of the sample?
_________________________
Why is it necessary to make a blank and measure the absorbance of the blank before measuring the sample absorbance?
= 0.354
0.354 = 0.001x
x = 179
_________________________
The primary purpose of a blank sample is to identify potential sources of sample contamination and assess the magnitude of contamination with respect to concentration of target analytes.