High accuracy technique revolutionizes platinum group metals assay. (General Developments).

NIST researchers have developed a high performance approach to the measurement of elemental composition using inductively coupled plasma optical emission spectroscopy. This technique uses an innovative experiment design coupled with a novel drift correction approach to minimize and quantify the major sources of uncertainty in this chemical analysis. A recent publication documents the performance of the method, high performance inductively coupled plasma optical emission spectrometry, for 64 elements where the typical relative expanded uncertainty observed is 0.1% (Analytical Chemistry 73, 4821-4829, 2001). This technique utilizes unmodified, commercially available equipment, is well suited to automation, and yields results comparable to the best attainable by classical methods.

The NIST researchers presented this technique and results at an ASTM E01 committee meeting in May 2001, and established a collaboration to implement it with a private company in North Attleboro, MA, a precious metals and advanced materials supplier. Together, methods for the determination of palladium and platinum in metallic samples were developed. NIST provided software tools to perform the calculations. Less than one year later, this technique was in routine use at the company, complementing the gravimetric wet chemical technique used in their labs. According to a company spokesman, "This technique has revolutionized our Platinum Group Metals assay lab. Assay completion times which ran 20 to 30 days, now average 4 to 6 days. Assay precisions have improved by more than an order of magnitude. Accuracy, as measured by the number of assays sent for umpire laboratory analysis, has improved to the point that we have not had to go to umpire in over three months. I am now setting up the procedure for the determina tion of gold at major levels."

CONTACT: Marc Salit, [phone]; [e-mail].