Samples fused under code 4B2 are diluted and analyzed by ICP-MS. Three blanks and five controls (three before the sample group and two after) are analyzed per group of samples. Duplicates are fused and analyzed every 15 samples. Instrument is recalibrated every 40 samples.
Elements and Detection Limits (ppm)
Typical ICP/MS Standards Analysis (119 measurements)
4B2-STDQuant: Although intended primarily for unmineralized samples, mineralized samples can be analyzed. However data may be semiquantitative for chalcophile elements (Ag, As, Bi, Co, Cu, Mo, Ni, Pb, Sb, Sn, W and Zn). A 1 g sample is digested with aqua regia and diluted to 250 ml volumetrically. Appropriate international reference materials for the metals of interest are digested at the same time. The samples and standards are analyzed on a Varian Vista 735 or a Thermo ICAP 6500 ICP.
Code 4B1 : recommended for accurate levels of base metals (Cu, Pb, Zn, Ni and Ag) .
Code 4B-INAA : recommended for As, Sb, high W >100 ppm and Cr > 1,000 ppm
Code 5D: recommended for Sn >50 ppm.