Gold Analysis was undertaken for a client who wanted to determine level of gold in their final effluent. As they were refining gold, they needed to ensure that the gold levels in their final effluent was kept as low as possible. You basically do not want your product to go down the drain.
The instrument used to do this analysis was the PDV6000ultra. This instrument was installed in the laboratory for this determination, but can also be used as a portable analyser in the field. The system runs on VAS software when connected to a PC (the software is supplied free of charge to all users of the instrument).
A sample was collected from the site. The sample appeared water like with a fine black suspension settled at the bottom. The pH was very acidic at pH 0,65.
The sample was scanned and immediatly saturated the system with a huge Au signal, obvious sample dilution was required.
A x10 dilution was employed and read directly against a pure standard.
The picture below is a screenshot from the VAS Software. The blue line is the sample resonse, the red is the Au Standard response: by simple peak height comparison the result generated an initial value of 30,94 mg/L (ppm) Gold.
Voltammogram of a x10 dilution sample compared to a Au (Gold) Standard:
Now that the sample was quantified, 3 standard additions were performed with the same Au Standard on this sample aliquot and the final resulting value was obtained through linear regression:
Gold value = 28,89 mg/L (ppm)
Correlation Coefficient = 0,997357