Tenax extraction as a simple approach to improve environmental risk assessments

Abstract

It is well documented that using exhaustive chemical extractions is not an effective means of assessing exposure of hydrophobic organic compounds in sediments and that bioavailability-based techniques are an improvement over traditional methods. One technique that has shown special promise as a method for assessing the bioavailability of hydrophobic organic compounds in sediment is the use of Tenax-extractable concentrations. A 6-h or 24-h single-point Tenax-extractable concentration correlates to both bioaccumulation and toxicity. This method has demonstrated effectiveness for several hydrophobic organic compounds in various organisms under both field and laboratory conditions. In addition, a Tenax bioaccumulation model was developed for multiple compounds relating 24-h Tenax-extractable concentrations to oligochaete tissue concentrations exposed in both the laboratory and field. This model has demonstrated predictive capacity for additional compounds and species. Use of Tenax-extractable concentrations to estimate exposure is rapid, simple, straightforward, and relatively inexpensive, as well as accurate. Therefore, this method would be an invaluable tool if implemented in risk assessments.

Implementing standardized desorption extraction into bioavailability-oriented bioremediation of PAH-polluted soils

“…One of the chemical methods which has been proposed is the desorption extraction with Tenax during 20 h, and it has recently been included in the only standardized bioavailability methodology (ISO method 16751), known so far [1][2][3][4] . Using Tenaxextractable concentrations in soils and sediments risk assessments has several advantages: is rapid, simple, straightforward, and relatively inexpensive 5 . In spite of these advances, further efforts are needed to demonstrate the wide aplicability of this methodology to a variety of HOCs and environmental matrices, for these approaches to finally settled down in environmental regulations.…”

Microbial bioavailability of 2,2′,4,4′-Tetrabromodiphenyl ether (BDE-47) in natural sediments from major rivers of China

“…Desorption of BDE-47 from sediments was described using the first-order kinetics model with three compartments (Harwood et al, 2015):…”

“…Tenax extraction method is an effective desorption-based way to estimate the bioavailability of HOCs in soils and sediments (Harwood et al, 2015). The mass balance was determined by comparing the sum of the quantity of BDE-47 sorbed on Tenax-TA beads and that remaining on the sediment with the original quantity on the sediment.…”