Examination of sol–gel technique applicability for preparation of pellets for soil analysis by laser ablation inductively coupled plasma optical emission spectrometry

The Use of Hyphenated Spectrometric Techniques for the Environmental Forensic Assessment of Non-Traditional Pollutants and Degradates in the Greater Florida Everglades

“…About a dozen manuscripts have been published in the last 13 years discussing the use of LA-ICP-MS and, to a lesser extent, LA-ICP-OES for the analysis of soils and sediments (Litche 1995;Hoffman 1997;Baker et al, 1999;Musil et al, 2000;Klem et al, 2001;Tao et al, 2002;Mikolas et al, 2002;Boulyga et al, 2004;Gilon 2005;Beccaglia et al, 2006;Hubova et al, 2007;Fernandez et al, 2008).…”

“…Some limitations remain on the existing methods; such as: a) these are either optimized for single element determinations (Tao et al, 2002;Boulyga et al, 2004) or for a limited suite of elements (Hubova et al, 2007;Mikolas et al, 2002;Boulyga et al, 2004;Fernandez et al, 2004), b) sample preparation compromises the quantitation of volatile compounds (Litche 1995), c) sample preparation remains labor intensive (Hubova et al, 2007;Musil et al, 2000;Mikolas et al, 2002), and/or requires the use of binders (Musil et al, 2000;Beccaglia et al, 2006;Mikolas et al, 2002;Mason et al, 2006;Boulyga et al, 2004), d) complex or expensive quantitation strategies are required to improve accuracy and precision (Baker et al, 1999;Hoffman et al, 1997;Hubova et al, 1997;Boulyga et al, 2004) or e) the effect of sample heterogeneity has not been effectively addressed (Hofmman et al, 1997;Klem et al, 2001;Boulyga et al, 2004;Fernandez et al, 2008).…”

“…The presence of large particles requires the use of either large laser spot sizes (of about 1 -2 mm) which may not be available in some UV-lasers; or the ablation of numerous craters (30-100 craters) to achieve a representative sampling of the bulk soil, which may not be practical in terms of time of analysis (Hofmman et al, 1997). Reported accuracy on laser ablation of soils has been generally ≤ 20% and ranging from 5 to 100% depending on many variables such as elements under study, sample preparation, concentration range, standard reference materials and calibration strategies (Litche 1995;Hoffman 1997;Baker et al, 1999;Musil et al, 2000;Klem et al, 2001;Tao et al, 2002;Mikolas et al, 2002;Boulyga et al, 2004;Gilon 2005;Beccaglia et al, 2006;Hubova et al, 2007;Fernandez et al, 2008).…”

“…Alternative sample preparation methods have also been recommended to improve homogeneity, such as the use of fusion with lithium borate (Litche 1995), methacrylate glue (Klemm et al, 2001) and the use of a sol-gel technique (Hubova et al, 2007).…”

“…Hubova's research group applied this sample preparation scheme for the successful analysis of 5 elements by using LA-ICP-OES and compared the results versus XRF and solution ICP-OES. Bias for a set of four soil samples was below 15% for most of the elements (ranging from 1 to 31% depending on the soil and the reference technique) (Hubova et al, 2007). The main disadvantage of this method is extensive sample preparation, since soils still have to be ground and pressed into pellets after the gel is created and dried overnight.…”