Technical details of 9999 pure gold

Dear Sir,

I like to introduce myself. This is Natarajan from Tanishq
jewellers,India.I need the details on the following.

Please suggest best way of 9999 pure gold testing method,
specification limits on elements present in it. And also please give
on ICP suppliers

You will be very helpful in our work.

Thanking you,

Natrajan.S
Quality Assurance
Tanishq
India.