Department of Applied Environmental Science, Stockholm University, Stockholm, Sweden.
Environ Toxicol Chem. 2013 Dec;32(12):2695-700. doi: 10.1002/etc.2361. Epub 2013 Oct 1.
Understanding the dietary absorption efficiency of chemicals in the gastrointestinal tract of fish is important from both a scientific and a regulatory point of view. However, reported fish absorption efficiencies for well-studied chemicals are highly variable. In the present study, the authors developed and exploited an internal chemical benchmarking method that has the potential to reduce uncertainty and variability and, thus, to improve the precision of measurements of fish absorption efficiency. The authors applied the benchmarking method to measure the gross absorption efficiency for 15 chemicals with a wide range of physicochemical properties and structures. They selected 2,2',5,6'-tetrachlorobiphenyl (PCB53) and decabromodiphenyl ethane as absorbable and nonabsorbable benchmarks, respectively. Quantities of chemicals determined in fish were benchmarked to the fraction of PCB53 recovered in fish, and quantities of chemicals determined in feces were benchmarked to the fraction of decabromodiphenyl ethane recovered in feces. The performance of the benchmarking procedure was evaluated based on the recovery of the test chemicals and precision of absorption efficiency from repeated tests. Benchmarking did not improve the precision of the measurements; after benchmarking, however, the median recovery for 15 chemicals was 106%, and variability of recoveries was reduced compared with before benchmarking, suggesting that benchmarking could account for incomplete extraction of chemical in fish and incomplete collection of feces from different tests.
从科学和监管的角度来看，了解鱼类胃肠道中化学物质的膳食吸收效率非常重要。然而，对于经过充分研究的化学物质，报告的鱼类吸收效率差异很大。在本研究中，作者开发并利用了一种内部化学基准方法，该方法有可能降低不确定性和变异性，从而提高鱼类吸收效率测量的精密度。作者应用基准方法来测量 15 种具有广泛物理化学性质和结构的化学物质的总吸收效率。他们分别选择 2,2',5,6'-四氯联苯（PCB53）和十溴二苯醚作为可吸收和不可吸收的基准物。鱼体中测定的化学物质的量与鱼体中回收的 PCB53 分数相基准，粪便中测定的化学物质的量与粪便中回收的十溴二苯醚分数相基准。基于测试化学物质的回收率和吸收效率的重复测试精度来评估基准程序的性能。基准化并没有提高测量的精密度；然而，基准化后，15 种化学物质的中位数回收率为 106%，回收率的变异性与基准化前相比有所降低，这表明基准化可以解释鱼类中化学物质不完全提取和不同试验中粪便不完全收集的问题。
