Development of methods for Mg, Sr and Pb isotopic analysis of crude oil by MC-ICP-MS: addressing the challenges of sample decomposition

Abstract

New approaches in isotope geochemistry require the development of novel methods for the isotopic analysis of crude oil, a typically complex and very hard to digest organic geological matrix. In...

Microwave-assisted hydrogen peroxide digestion followed by ICP-OES for determination of metals in selected fuel oils

“… SRM 1634c MA-HPD Ba, Na, Ni and V 9 mL of 5 M H 2 O 2 and 1 mL of conc. HNO 3 0.55–58.86 104.8–117.7 ≤ 4.1 0.046, 0.0304,0.408 and 0.057 ICP-OES This work Biodiesel MAAD Ba, Ni and V 10 mL of 7 M HNO 3 0.0027–0.101 95–108 < 6 0.00012,0.0028 and 0.00012 SF-ICP-MS 20 Crude oil MAAD Mg, Pb and Sr 6 mL of 14.4 M of HNO 3 Mg (12.5–201), Pb (0.09–0.203) and Sr (2.3–6.06) 95–104 < 4.0 0.1,0.3 and 0.07 MI-ICP-MS 36 Crude oil MAAD Na, Ca and Mg 4 M of H 2 O 2 and 5 mL conc. HNO 3 0.003–22.6 94–110 < 5 0.001–0.002 ICP-OES 5 Crude oil MAAD Ni and V 5 mL of 4 M H 2 O 2 and 10 mL of 5 M HNO 3 2–230 94.6–98.2 < 4.62 0.237 and 0.060 ICP-OES 37 Diesel MAAD Al, Cu, Fe, Ni and Ni 4 mL conc.…”

“…Despite the absence of Mg in station C of the crude oil fractions, it must be noted that the metals that reported high concentrations in overall samples included Mg (36.08–47.40 mg/kg) and Na (51.94–58.86 mg/kg). The presence of Na and Mg is not favoured, mostly in diesel and gasoline as these metals promote rapid deposit build up in vehicle engine which in turn can lead to deterioration of exhaust gas after treatment systems 36 . The concentration levels of Cu were very small in all the investigated filling stations.…”

Atomic spectrometry update: review of advances in the analysis of metals, chemicals and materials

“…Analysis was achieved using ICP-MS with an assortment of internal standards introduced as a mixture on-line rather than being spiked into individual samples. The internal standards used were 45 Sc for those elements with a mass up to and including 59 Co, 72 Ge for the analytes 62 Ni to 95 Mo, 125 Te for 101 Ru to 137 Ba, 175 Lu for the analytes 189 Os to 197 Au and 209 Bi for analytes with a higher mass. Any polyatomic interferences were removed through the introduction of helium at a ow rate of 5 mL min −1 into the collision/reaction chamber.…”

“…The first paper in this section, by Henn et al , described a microwave digestion method for the Mg, Pb and Sr isotopic analysis of crude oil . 95 This method was compared with the ASTM D4807 method of decomposition. Column chromatographic protocols for target element isolation were fine-tuned for each analyte to ensure quantitative yields.…”

Atomic spectrometry update: review of advances in atomic spectrometry and related techniques

“…Measurement of Sr, Pb and Mg isotopes in crude oil was investigated by Henn et al 163 who trialled two methods – microwave-assisted wet digestion within an ultra-high pressure digestion cavity and solubilisation of inorganic solids using membrane filtration. The latter method did not retain Pb, possibly due to its affinity with unrecovered organic compounds, but both methods satisfactorily recovered Sr and Mg.…”