Chromium was only detected in nitric acid and
aqua regia solutions of sample 6.
The
aqua regia method of analysis is susceptible to acid interference, which makes it unreliable if used alone.
b Wet-digestion with HNO3 andH2O2 (2:1) on hot plate, c Wet-digestion with mixture of HNO3 and HClO4 on hot plate, d Wet-digestion with
aqua regia on hot plate, e Wet-digestion with reverse
aqua regia on hot plate, f Wet-digestion with mixture of HNO3 and H2SO4 on hot plate, g Wet-digestion with mixture of HNO3 and HF on hot plate.
The
aqua regia digest results are presented in Table 2.
Soil samples are dried at low temperature, screened to 80 mesh (MSA code PRP-757), a 15 grams portion is then assayed for a multi-elements suite (MSA code IMS-136,
Aqua Regia digestion, ICP-AES/MS finish).
The soil samples were digested by using
aqua regia method and the aliquots obtained were analysed by using Atomic Absorption Spectrophotometer to determine the concentration of heavy metals in the samples.
Entree soil samples were also submitted to Skyline for 49 element,
Aqua Regia digestion, TE-3 ICP/MS analysis.
Platinum deposits are soluble only in hot
aqua regia so stripping reject work is not really an option.
The samples were digested with HF-HCl[O.sub.4] (Lim and Jackson 1982) and with
aqua regia (Zarcinas et al.
Both labs used similar assay procedures: a 0.5g split of the -0.075mm fraction of the -80 mesh material underwent digestion with
aqua regia and the liquid was analyzed for 48 elements by ICP-MS; Apart from being analyzed by ICP-MS, gold was also analyzed by fire assay with an ICP-AES finish.