Field Sampling with a FP‐XRF: A Real‐World Lab Experience

Abstract

A field sampling laboratory experiment was developed so students would gain experience sampling on a field site and have an introduction to XRF spectrometry. The experiment used a rented field portable XRF instrument (FP-XRF) to quantify the lead in soil samples collected adjacent to an urban highway and explored aspects of the USEPA Method 6200. Rainy weather conditions eliminated the possibility to record spectra in the field, so sample preparation procedures were modified to model the typical in situ and intrusive mode of spectral investigations stated in the method. The lead content in the soil samples collected at 15 ft from the highway were determined to be greater than 2000 ppm. The soil lead content decreases as the distance perpendicular to the highway increases. The site background sample collected from 300 ft away is nearly equal to the instrumental lead detection limit of 20 ppm. ORDER REPRINTSThe experiment demonstrated the need to collect replicate spectral data for in situ sampling and that sample homogenization is a critical step in the intrusive sample analysis mode.

Comparison of XRF and PXRF for analysis of archaeological obsidian from southern Perú

“…A major advantage of PXRF is that instruments can be transported easily into the field or to museums, thereby permitting multi-element analyses of archaeological materials in non-traditional laboratory environments. PXRF has witnessed extensive geological and environmental applications since at least the early 1980s (Nissenbaum et al, 1981;Pandey et al, 1983;Rhodes and Rautala, 1983) and its use has proliferated since the mid-1990s (Bachofer, 2004;Bernick and Campagna, 1995;Clark et al, 1998;Kalnicky and Singhvi, 2001;Potts et al, 1995Potts et al, , 1997Thomsen and Schatzlein, 2002). Nonetheless, relatively few archaeological applications exist (Morgenstein and Redmount, 2005;Romano et al, 2005;Wager et al, 2002;Williams-Thorpe et al, 2003).…”

Potentially Harmful Elements in Urban Soils

“…In addition to the aqua regia leaching, the microwave-assisted digestion (US EPA 2007) and the nitric acid extraction (Tam and Yao 1999) were tested by the authors. Recently, also the non-destructive XRF spectrometry has gained attention for its simple use for quick PHE screening in soils and other materials (US EPA 1998;Bachofer 2004). Additionally, several studies have tested simpler extraction procedures to be used as predictors of the total PHE content in soil.…”

Atomic spectrometry update. Environmental analysis

“…The method used the partitioning of REE with solid hydroxides to separate them from soluble matrix species, such as Ba 21 and major ions. Acidified samples were spiked and equilibrated with an enriched isotopic mix of 142 Ce, 145 Nd, 161 Dy and 171 Yb, prior to co-precipitation of the analytes with small amounts of Mg 21 and Mg(OH) 1 present in the sample, using aqueous ammonia. The precipitate was isolated by centrifugation and washed to remove Ba 21 (99.8% removal efficiency) and the majority of matrix ions.…”