The titration is probably ultimately more accurate, but is very tedious if done manually, or quite expensive if you have to buy an automated titrator. And, you only get a silver result.
The cupellation method has the advantage of reporting both the gold and silver (needed for bullion analysis), and is quite accurate if done by a proper corrected method.
The SMA (http://www.sma-online.org) had a bullion committee which developed a corrected cupellation method which was ultimately adopted by the ASTM.
The cupellation method has the advantage of reporting both the gold and silver (needed for bullion analysis), and is quite accurate if done by a proper corrected method.
The SMA (http://www.sma-online.org) had a bullion committee which developed a corrected cupellation method which was ultimately adopted by the ASTM.
I haven't seen the ASTM procedure for a while. As I recall there was not anything out of the ordinary.
Be sure you run a preliminary bullion assay to determine the proper amount of gold, silver, and copper to add to your "proof". This will give you the proper corrections. The gold, silver, and copper used for the proof should be high purity.
Be sure you run a preliminary bullion assay to determine the proper amount of gold, silver, and copper to add to your "proof". This will give you the proper corrections. The gold, silver, and copper used for the proof should be high purity.