Trace element survey analyses

Trace Element Survey Analyses by Spark Source Mass Spectrography... 

LEIPZIGER AND GUIDOBONI Trace Element Survey Analyses... 

Although SSMS cannot be considered a surface technique due to the 1-5 rm penetration of the spark in most materials, few other techniques can provide a trace elemental survey analysis of surfaces consisting of films or having depths of interest... 

Abel, Trace Elemental Survey Analysis of TNT , PATR 4257 (1975) 76) T.H. Maugh,... 

H. Kramer, S. Semel J.E. Abel, Trace Elemental Survey Analysis of Trinitrotoluene , PATR 4767 (1975) (An evaluation of the applicability of spark source mass spectrometry and thermal neutron activation for the detn of origin-related trace elemental impurities in TNT) 10) C. Ribando J. Haber-man, Origin-Identification of Explosives Via Their Composite Impurity Profiles I. The... 

Evans, C.A. and G.H. Morrison, 1968, Trace element survey analysis of biological materials by spark source mass spectrometry. Anal. Chem. 40, 869. 

Trends in element analysis are multi-element (survey) analysis, lower concentration levels, micro/local element analysis and speciation (coupling with chromatography). An overview of the determination of elements in polymeric materials is available [7], Reviews on sample preparation for trace analysis are given in refs [8-10]. Quality assurance of analytical data in routine elemental analysis has been discussed [11], Organic analysis is obviously much more requested in relation to polymer/additive matrices than elemental analysis. 

A particular advantage of ICP-MS derives from its ability to display a complete mass spectrum at one time. Combined with sample introduction by laser ablation it constitutes a very powerful tool for first-look analysis, e g. in geological prospecting or ecological surveys. ICP-MS is applicable to the whole range of areas where minor or trace elements are to be determined. 

Very little data have been reported on the analysis of elements in whole coal and mine dusts in particular. Kessler, Sharkey, and Friedel analyzed trace elements in coal from mines in 10 coal seams located in Pennsylvania, West Virginia, Virginia, Colorado, and Utah (5). Sixty-four elements ranging in concentration from 0.01 to 41,000 ppm wt were determined. Several surveys published previously have provided data on the concentration of minor elements in ashes from coals rather than a direct determination on the whole coals or mine dusts. Previous investigations include studies by Headlee and Hunter (6), Nunn, Lovell, and Wright (7), Abernethy, Peterson, and Gibson (8), and others (9, 10, 11,12). 

Our results indicate that x-ray fluorescence is highly useful for rapid and reasonably accurate analyses of whole coal for trace elements. Because of the speed and simplicity of the method, it is highly adaptable to large-scale surveys of coal resources. A suite of 24 samples can be analyzed for 21 elements in 3 days by manual instrumentation. While this simple procedure can not be used to determine certain elements, the time-saving factor over other methods (40 or 50 to 1 in the case of bromine by neutron activation) without loss of accuracy may well make x-ray fluorescence the method of choice for many elements. Improved equipment, such as nondispersive systems and automation, could extend the application of x-ray analysis to a dominant position for determining trace elements in whole coal. 

Additional surveys of the area by Sarah Brooks were successful in locating a large deposit of obsidian 5 km east of the the town of Chivay. An independent survey by Burger and Peruvian geologist Guido Salas in 1995 also located the source, which they dubbed the Chivay source their publications of the results along with the analysis at LBNL provided the first detailed description of the source location and the trace element chemistry (77). The source was referred to as Cotallalli by Brooks (46) but most of the literature now refers to the source as Chivay (47-49). 

Some refractory elements cannot be determined by ET-AAS at the levels usually present in waters. That is the case with M. El Himri et al. [28] developed a fast and accurate procedure, without any prior treatment, to analyze tap and mineral waters from Spain and Morocco for this highly toxic element. ICP-MS was employed. The analytical isotope selected was 238U, with Rh as internal standard. An LoD of 2ngl 1 was obtained. The estimated repeatability was 3 percent at the concentration level of 73 ng l-1. The method was validated by comparison with a radiochemical procedure devised for natural samples and by analysis of a Certified Reference Material (CRM). Multi-element capabilities of ICP-AES have also been employed for surveys of trace elements. Al-Saleh and Al-Doush [29] reported the concentrations of dissolved Be, Cd, Cr, Cu, Fe, Mg, Mn, Hg, Ni, Se, Sr, V, and Zn in 21 samples of retail bottled waters from Riyadh, Saudi Arabia. It was found that Cd, Fe, Hg, Ni, and Zn were present at concentrations higher than the limits recommended by the EU and World Health Organization (WHO) guidelines. 

The focus of this research and other mass balance studies has been on trace elements (1,2,3). However, in future studies on speciation it will be necessary to know the concentrations of the elements present in amounts above 1%. Therefore, analyses of the oil shale and spent shale samples were performed for these elements. Atomic absorption and colorimetry were used for many of these analyses. Some major element results also were obtained by the broad-range instrumental analysis surveys. The comparison of the results obtained by the different techniques shows large discrepancies. 

Dc arc spectrography is still a most powerful method for trace determinations in solids even with difficult matrices such as U3Og. Here the detection limits for many elements are down in the sub-pg/g range [358]. It is still in use for survey analysis, especially in the case of ores, minerals and geological samples. In work with unipolar arcs, re-ignition of the arc is often facilitated by providing an hf discharge over the dc arc, by which the arc channel is kept electrically conductive. 

Many chemical models have been developed over the years for problems solving chemical speciation. A comprehensive survey of many of the models and detailed analysis of computer modeling in relation to trace element speciation has been by made by Waite (1989), with particular reference to MINEQL, and by Lumsdon and Evans (2002), with particular reference to MITEQA2. Soil solution has significant amounts of DOM, which is poorly quantified and understood. The trace element speciation information obtained using computer modeling with data on complexation constants of metal—DOM complexes has to be substantiated with data on free metal ion species obtained from sophisticated physical techniques. 

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