Problems with Sb analysis of environmentally relevant samples

Abstract

Environmental context. Reliable results of chemical analysis are crucial for a proper environmental risk assessment. The recovery of antimony concentrations in environmentally relevant samples is here shown to be most dependent on the extraction method chosen. A reported low antimony concentration in present or historical samples may be misleading for decision-makers. Abstract. Antimony is found in elevated concentrations in the roadside environment, industrial sites and generally in urban areas. An extended use of multielement analysis has produced more concentration data for metals in the environment. However, volatilisation of elements in the digestion step may be a problem as some of the certified and recommended digestion methods are performed in open vessels. The aim of the current study was to focus on wet digestion-derived problems for the analysis of volatile elements, with specific reference to Sb. Both soils and products, namely tyres and brake linings, were sampled. The samples were digested using different methods with variations in temperature, acid mix, and the use of open or closed vessels. For some methods, the recovery was <10%, indicating a need for revision of certified and recommended digestion procedures. For a multielement analysis, a closed vessel method must be used. If the aim is to study only Sb, a wet-digestion method optimised for Sb is the natural choice. This may be valuable to consider when handling environmentally relevant samples such as soils contaminated with Sb from point or diffuse sources.

Antimony leaching from soils and mine waste from the Mau Due antimony mine, North-Vietnam

“…The recovery of Sb concentrations from environmental samples depends on the extraction method chosen (Hjortenkrans et al, 2009). Therefore, the choice of reagents for sample digestion requires careful consideration to ensure adequate matrix dissolution and prevent the formation of insoluble Sb-bearing precipitates (Nash et al, 2000).…”

Assessing toxicity of metal contaminated soil from glassworks sites with a battery of biotests

“…The received concentrations can be viewed as total, or pseudo-total. To get an efficient extraction of Sb, the addition of hydrochloric acid (HCl) is needed (Hjortenkrans et al 2009). This element was therefore determined after an aqua regia extraction, where a 0.5 g subportion of the material was digested using 7.5 mL concentrated HCl and 2.5 mL concentrated HNO3.…”

Atomic spectrometry update. Environmental analysis

“…178 The environmental chemistry of Sb has been reviewed 179 and the need for improved analytical methods for Sb highlighted. Hjortenkrans et al 180 have described the optimisation of methods for the recovery of Sb from urban samples, including soils.…”