Lab BCH 2333

Section:

Lab 1 Carbohydrates: Separation Techniques Based on Molecular Size

TA:

Wednesday, January 16th, 2013

Team #4

By:

Partner:

Purpose

The purpose of this experiment is to exemplify how differences in molecular weight allow separation of polymers from their monomers. Methods of dialysis and gel filtration chromatography will be used to separate a glucose monomer from a starch polymer. Colorimetric glucose oxidase assay will be used to monitor the presence of glucose and a colorimetric iodine assay will be used to monitor the presence of starch in prepared solutions after separation

Results and Discussion

Table 1: Glucose oxidase …show more content…

R7

Kav = (Ve-Vo)/(Vt-Vo)

Vt = π(d/2)2h

d= 0.9cm h=46.5cm Vo = 15.0mL
Ve-starch = 15.4mL
Ve-glucose = 30.9mL

Vt = π(d/2)2h =π(0.9cm/2)2(46.5cm) =29.6cm3 = 29.6mL

Glucose

Kav = (Ve-Vo)/(Vt-Vo) = (30.9mL-15.0mL)/(29.6mL-15.0mL) = 1.09

Starch

Kav = (Ve-Vo)/(Vt-Vo) = (15.4mL-15.0mL)/(29.6mL-15.0mL) = 0.0274

The average distribution coefficient (Kav) of the glucose is 1.09, which is reasonable because glucose is a small molecule. Small molecules should have a Kav value close to 1. The average distribution coefficient (Kav) of the starch is 0.0274, which is reasonable because starch is a bigger molecule. Bigger molecules should have a Kav value close to 0.

R8

Glucose

Total mass from 15 fractions: 24.2mg
Concentration of glucose in glucose/starch mixture: 47.3mg/mL
Volume of mixture applied to column: 0.5mL

Theoretical recovery yield of glucose
= (Concentration of glucose in glucose/starch mixture)(Volume of mixture applied to column)
= (47.3mg/mL)(0.5mL)
= 23.7mg

Experimental recovery yield of glucose (%)
= (Total mass from 15 fractions)/(Theoretical recovery yield of glucose)*100%
= (24.2mg)(23.7mg)*100%
= 102%

Starch

Total mass from 15 fractions: 0.952mg
Concentration of starch in glucose/starch mixture: 1.03mg/mL
Volume of mixture applied to column: 0.5mL

Theoretical recovery yield starch
= (Concentration of starch