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

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.

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

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

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

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

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+0.175 x=139

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=x3 _ ----------------------------------- = 138.33 = X 3=n

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

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

Question Given the standard calibration curve equation y=0.001x+0.175 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.