It is important to evaluate different digestion methods to accurately determine elemental concentrations in soils. Three commonly used digestion procedures, hotplate aqua regia, microwave aqua regia, and microwave aqua regia + HF, were compared for digestion of three standard reference materials (SRMs 2704, 2709, and 2711) and 20 Florida soils (three groups of Quartzipsammemts, one group of Alaquods, and one group of Paleudults). Sixteen elements (Al, Ba, Ca, Fe, K, Mg, Mn, P, Zn, As, Cd, Cr, Cu, Ni, Pb, and Se) were analyzed using either an inductively coupled plasma optical emission spectrometer (ICP-OES) or a graphite furnace atomic absorption spectrophotometer (GFAAS). Precise analysis was achieved for all elements except As (1.0-25%), Cd (1.8-22%), and Se (4.1-22%) in the SRMs using all three procedures, with the microwave aqua regia + HF procedure having slightly better precision (3.7%) averaged across all elements. Compared with the elemental recoveries in SRMs by the microwave aqua regia digestion (80%), microwave aqua regia + HF digestion achieved greater accuracy (94%), whereas the hotplate aqua regia digestion achieved less accuracy (74%). In general, the microwave aqua regia + HF digestion was overall the best procedure for determining concentrations of most metals in SRMs and Florida soils, followed by the microwave aqua regia and the hotplate aqua regia digestion. However, this so-called total-total digestion procedure (microwave aqua regia + HF) may underestimate total Pb concentration in Florida soils and total Al, Ca, Fe, Mg, and Ba concentrations in the Florida Paleudults.

Comparison of Three Aqua Regia Digestion Methods for Twenty Florida Soils

Antimony in the environment as a global pollutant: a review on analytical methodologies for its determination in atmospheric aerosols.

Acid interferences in atomic spectrometry: analyte signal effects and subsequent reduction

The determination of trace elements in crude oil and its heavy fractions by atomic spectrometry

Determination of vanadium in petroleum and petroleum products using atomic spectrometric techniques

Trace elements in fuel oils have been analysed by inductively coupled plasma mass spectrometry (ICP-MS) after acid solubilization of the samples in a microwave oven. The results relative to the National Institute of Standards and Technology SRM 1634b and SRM 1619 show good accuracy and precision for about 20 elements. The detection limits are, for most of the elements, in the range 0.02–0.2 µg g–1; values that are consistent with the concentrations of metallic impurities present in fuel oils. The good agreement obtained on real samples using neutron activation analysis is a demonstration that ICP-MS can compete with a well established reference technique for the determination of trace metals in fuel oil.

Determination of trace elements in fuel oils by inductively coupled plasma mass spectrometry after acid mineralization of the sample in a microwave oven

The method previously described by Casetta et al. for the determination of aluminium in dilute (1 + 1) human serum using matrix modification and a stabilised temperature platform furnace has been considered. The combination of the platform, integrated absorbance, new coated tubes and oxygen addition to the charring step, provided better precision and smaller variation during the life of the tube. Good results were achieved by standardising the procedure against a calibration graph if integrated absorbance signals were used for quantitation. The calibration was linear up to at least 150 µg l–1 of aluminium; the within-run and between-run precision was 5.5 and 6.5%, respectively (at 14.3 µg l–1 of aluminium); and the recovery of aluminium added to pooled serum ranged between 97 and 102%. Furnace lifetimes in excess of 200–250 firings using oxygen ashing were routinely achieved.

Evaluation of the L'vov platform and matrix modification for the determination of aluminium in serum

Three different procedures for the simultaneous determination of major and trace elements in coal fly ashes and geological samples by inductively coupled plasma atomic emission spectrometry are compared. Dissolution of the samples is achieved by a high-temperature fusion with Li2B4O7 and subsequent dissolution in hydrochloric acid, or with a mixture of hydrofluoric, nitric, perchloric or hydrochloric acids by heating in a PTFE bomb or in a microwave oven. The accuracy of the methods are confirmed by analysis of six different NBS reference materials (1633 and 1633a coal fly ash, 1645 river sediment, 1646 estuarine sediment, 278 obsidian rock and 688 basalt rock). The relative standard deviations vary from 1–10%

Analysis of coal fly ash and environmental materials by inductively coupled plasma atomic emission spectrometry: comparison of different decomposition procedures

Four decomposition procedures for coal fly ash samples were investigated for the subsequent determination of arsenic, cadmium, antimony, selenium, lead and thallium. Decomposition with nitric acid under pressure in a PTFE bomb or microwave oven was adequate for the determination of As and Se but resulted in low values for all the other elements. Decomposition with nitric, hydrofluoric and perchloric acids in a PTFE bomb could be utilised for As, Se, Cd, Pb and Tl determinations whereas Sb was partly lost under these conditions. Decomposition with nitric, hydrofluoric and hydrochloric acids in a microwave oven was applicable for all the elements and gave results that were in good agreement with the certified values. The stabilised temperature platform furnace (STPF) technique with Zeeman-effect background correction was used for the determination of all the elements. After decomposition of the samples, calibration graphs were constructed using aqueous standards; use of standard additions was unnecessary for all the elements when using a Pd-Mg(NO3)2 mixed modifier. The atomic absorption spectrometry (AAS) results for As, Sb and Se were compared with those obtained by neutron activation analysis (NAA).

Determination of arsenic, cadmium, lead, antimony, selenium and thallium in coal fly ash using the stabilised temperature platform furnace and Zeeman-effect background correction

Determination of Trace Elements in Power Plant Emissions by Inductively Coupled Plasma Mass Spectrometry: Comparison with Other Spectrometric Techniques

U. Baroni

Papers

Determination of trace elements in fuel oils by inductively coupled plasma mass spectrometry after acid mineralization of the sample in a microwave oven

Evaluation of the L'vov platform and matrix modification for the determination of aluminium in serum

Analysis of coal fly ash and environmental materials by inductively coupled plasma atomic emission spectrometry: comparison of different decomposition procedures

Determination of arsenic, cadmium, lead, antimony, selenium and thallium in coal fly ash using the stabilised temperature platform furnace and Zeeman-effect background correction

Determination of Trace Elements in Power Plant Emissions by Inductively Coupled Plasma Mass Spectrometry: Comparison with Other Spectrometric Techniques