K 44

1
DETERMINATION OF GLUCOSE IN BLOOD STREAM

• K 4-4
• By Haseeb Quadri

2
CALIBRATION CURVEMass 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) 1000 mg
• ------------------------------------- x
  --------------- x (volume of stock dilution)
• 100 ml
  1 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-
• 1.0013 grams 1000 mg
• --------------------- x -------------- x
  (5 ml) 50.065
• 100 ml 1 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 AnalysisAbsorbance

• 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-
• y0.001x0.175
• for absorbance one-
• 0.314 0.001x0.175 x139

8
Average mg/100ml

• take all the concentration at each absorbance
  and add them up _
• ------------------------------------------------
  ----------------------------- X
• the amount of trials that are
  taken
• Sample calc.
• 139x1 135x2 141x3
  _
• -----------------------------------
  138.33 X
• 3n

9
Standard Deviation

• (139-138.33)2(135-138.33)2(141-138.
  33)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
  y0.001x0.175 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?

• 0.356- 0.002 0.354
• 0.354 0.001x 0.175
• 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.