Date of Award
Bachelor of Science (Applied and Analytical Chemistry) Honours
School of Natural Sciences
Faculty of Health, Engineering and Science
Dr Magdalena Wajrak
Associate Professor Mary Boyce
This work presents a reliable, cost-effective, rapid and infield voltammetric method for the detection of barium. The optimized method consists of an ultrathin mercury film deposited in-situ on a glassy carbon electrode in 0.02 M potassium chloride without deoxygenation; a deposition potential of -2500 mV, pulse height = 50 mV, step duration = 10 ms and a scan rate of 100 mV/s using differential pulse anodic stripping voltammetry (DP-ASV).
The linear working range for barium was determined to be 5 – 80 μg/L (r2 = 0.997), and limit of detection (LOD) was 1.6 μg/L, for 30 sec deposition time. Percent relative standard deviation for 10 measurements performed at 20 μg/L was 5.8%.
Application of the method allowed for the quantitative determination of barium concentration in a variety of waters, brake pad dust and gunshot residue (GSR) samples. Comparative analysis of sample results from DP-ASV with inductively-coupled plasma mass spectroscopy (ICP-MS) showed a mean percent difference of 1.8%. The method also permitted the simultaneous measurement of barium and lead, crucial for GSR samples.
Ridgway, S. N. (2015). Development of an in-field voltammetric method for the determination of barium. https://ro.ecu.edu.au/theses_hons/1472