The CSIRO analyses were performed on an inductively coupled plasma–atomic emission spectrometer (ICP-AES) calibrated using aqueous elemental standard solutions with a calibration range to suit samples compositions. Samples were decomposed in multiacid solutions and analyzed along with at least two blanks and international reference materials. For silicon, a separate digestion was prepared in a sealed teflon container. Major element oxides reported in weight percent are SiO2, TiO2, Al2O3, Fe2O3(t), MnO, MgO, CaO, Na2O, K2O, and P2O5. Trace elements reported in parts per million are Li, Be, S, Sc, V, Cr, Co, Ni, Cu, Zn, As, Sr, Y, Zr, Mo, Ag, Cd, Sb, Ba, La, Yb, and Pb.
CSIRO uses a quadruple design inductively coupled plasma–mass spectrometer (ICP-MS) as the detection device, and the entire mass range from 1 to 269 atomic mass units may be scanned in milliseconds. Samples were prepared as for ICP-AES. Trace elements reported in parts per million are Sc, V, Cr, Co, Ni, Zn, As, Rb, Y, Mo, Cd, In, La, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, and Pb. Trace elements reported in parts per billion are Sb, Te, Cs, Tl, Bi, Th, and U.
X-ray fluorescence (XRF) was used to measure major and trace elements on fused beads. Beads were prepared with LiBO2 flux on an automated fusion machine casting into 40 mm beads. Oxidizing conditions were used to prevent loss of sulfur and reduction of metals from the sample melt. Chlorine is lost from the glass and is only indicative of the concentration in the sample. The calibrations were derived from processing a large set of international and in-house reference and pure chemical samples; analyses are routinely checked with in-batch reference samples and minimum 10% repeat samples. Loss on ignition analysis was done on a separate portion of the sample at 1050°C. Major element oxides reported in weight percent are SiO2, TiO2, Al2O3, Fe2O3(t), MnO, MgO, CaO, Na2O, K2O, and P2O5. Trace elements reported in parts per million are S, Cl, V, Cr, Co, Ni, Cu, Zn, Ga, Rb, Sr, Y, Zr, Nb, Ba, La, Ce, and Pb.
Neutron activation analyses (NAA) were performed at Becquerel Laboratories, Lucas Heights, NSW Australia. Fe2O3, Na2O, and K2O are reported as weight percent. Trace elements reported in parts per million are Sc, Cr, Co, Zn, Ga, Ge, As, Se, Br, Rb, Zr, Mo, Ag, Cd, Te, Cs, Ba, La, Ce, Sm, Eu, Yb, Lu, Hf, Ta, and Hg. Trace elements reported in parts per billion are Sb, Ir, Au, Th, and U.
Major element oxide and trace elements were measured by XRF on fused beads. The major elements SiO2, TiO2, Al2O3, Fe2O3(t), MnO, MgO, CaO, Na2O, K2O, and P2O5 are reported as weight percent oxides and Ba, Rb, Sr, Y and Zr are reported in parts per million.
TiO2, Al2O3, Fe2O3, MnO (reported in weight percent) and trace elements (Sc, V, Co, Ni, Cu, Zn, Ga, As, Rb, Sr, Y, Zr, Nb, Mo, Ag, Cd, Sb, Ba, La, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Tl, Pb, Bi, Th, and U, reported in parts per million) were analyzed by ICP-MS. Solutions were prepared using hydrofluoric and nitric acids under atmospheric conditions.
Samples were prepared by fusing with LiBO2 flux and dissolving the molten sample in acid. Standard reference materials (U.S. Geological Survey [USGS] BIR-1, BHVO-1, and W-2) and blanks were prepared using similar techniques. The major element oxides SiO2, TiO2, Al2O3, Fe2O3(t), MnO, MgO, CaO, Na2O, K2O, and P2O5 are reported in weight percent. Sc and Ba are reported in parts per million.
Samples for trace element analysis were prepared in the same manner as those for ICP-AES analyses. V, Cr, Co, Ni, Cu, Zn, Ga, Rb, Sr, Y, Zr, Nb, Cs, La, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, and Pb are reported in parts per million. Au is reported in parts per billion.