title: Solid-phase microextraction for predicting the bioavailability of 2,4,6-trinitrotoluene and its primary transformation products in sediment and water.
abstract: Disposable solid-phase microextraction fibers (SPMEs) were used to measure the availability of 2,4,6-trinitrotoluene (TNT) and its two primary transformation products, 2-amino-4,6-dinitrotoluene (2ADNT) and 4-amino-2,6-dinitrotoluene (4ADNT). The SPMEs (85-microm polyacrylate) and sediment-dwelling oligochaetes (Tubifex tubifex) were exposed to TNT-spiked sediment, to TNT-spiked sediment amended with activated carbon, and to TNT-, 2ADNT-, and 4ADNT-spiked water. Sediment concentration was a poor predictor of bioavailability in unamended and carbon-amended sediments (r2 = 0.14-0.73) The activated carbon amendment reduced the bioavailability of compounds in carbon-amended sediment, causing the relationships between Tubifex concentrations and sediment concentrations to differ significantly between unamended and carbon-amended sediment for all compounds. In contrast, SPME TNT concentrations predicted Tubifex TNT concentrations (r2 = 0.54-0.79). and regression models did not differ significantly among the three TNT-spiked matrices. The SPME 2ADNT and 4ADNT concentrations also were predictive of Tubifex 2ADNT and 4ADNT concentrations (r2 = 0.44-0.90). Relationships between Tubifex concentrations and SPME concentrations were the same between unamended and carbon-amended TNT-spiked sediments for 2ADNT and 4ADNT; however, the relationship in sediment (pooled data) differed from the relationship found in 2ADNT- and 4-ADNT-spiked water. The SPMEs provided carbon amendment-independent measures of ADNT availability in sediment and matrix-independent measures of TNT availability among the three matrices. The SPMEs show promise for predicting bioavailable organic compounds in sediment and water.
authors.affiliation: University of North Texas, Department of Biological Sciences, Institute of Applied Sciences, P.O. Box 310559, Denton, Texas 76203, USA. jconder@environcorp.com
authors.forename: Jason M
authors.initials: JM
authors.lastname: Conder
authors.forename: Thomas W
authors.initials: TW
authors.lastname: La Point
mesh_terms: D000818:Animals; D001682:Biological Availability; D002244:Carbon / Q000737:chemistry; D004784:Environmental Monitoring; D005618:Fresh Water / Q000737:chemistry*; D019015:Geologic Sediments / Q000737:chemistry*; D009835:Oligochaeta / Q000378:metabolism*; D014303:Trinitrotoluene / Q000032:analysis* / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000378:metabolism
chemical_list: D014874:Water Pollutants, Chemical; D014303:Trinitrotoluene; D002244:Carbon