# User:Alexander Cvitan/Notebook/Experimental Biological Chemistry Lab/2013/09/11

Biomaterials Design Lab Main project page
Previous entry      Next entry

## Objective

• To run atomic absorption spectra for gold solution standards as dictated by Dr.Hartings here.
• Form a calibration curve with the class data to use for future reference.
• Calculate Concentration of Gold in Citrate Au-NP's and BSA Au-NP's.
• Calculate the number of gold particles in each sample of Citrate Au-NP's and BSA Au-NP's.

## Procedure

• Samples were prepared as dictated by the table below.

• Please note that all samples were measured using a 100-microliter pipette and a 1000-microliter pipette.

## Data

### Individual and Group Calibration Curve

• The table below represents the results from the atomic absorption spectra. Please note that the max absorbance of gold was 248 nm.
• Also note that the Citrate Au-NP had to be diluted in order view on AAS. Further calculations must reflect this dilution.

• Absorbance had to be corrected in order to reflect the non-zero water absorbance.

• Note individual data is on the left and the class data is on the right.

### Grubbs Test Analysis of Group Data

• Based on the Grubbs test, and using a value of n=5 for each concentration, no data point had a Grubbs value greater than 1.67 using 95% confidence.
• Do to this fact none of the data points are outliers.

### Calculation of Concentration of Gold in Citrate Au-NP's and BSA Au-NP's

• Note that the best fit of the calibration curve is a polynomial.
• Using this best fit and the calculated absorbances of the Au-NP's the concentration of gold are the following,
• Concentration of Gold in Citrate Au-NP's = 74.45 ug/ml (This takes into account the dilution).
• Concentration of Gold in BSA Au-NP's = 38.35 ug/ml

### Calculation of the # of Gold Particles in each Au-NP

• Volume of BSA Au-NP = 2.809ml
• Using the concentrations calculated using the AAS the amount of gold in the whole solution is, .00000106 moles.
• Using avogadros number their is, 6.383 * 10E17 atoms of gold in the BSA Au-NP solution
• Volume of Citrate Au-NP = 25.6 ml
• Using the concentrations calculated using the AAS the amount of gold in the whole solution is, .00000498 moles
• Using avogadros number their is, 2.999 * 10E18 atoms of gold in the citrate Au-NP solution.
• Know the concentration of the nanoparticles in solution is 8.43 nM