Determination of lipid content in fish samples from bioaccumulation studies: contributions to the revision of guideline OECD 305

Abstract

Background: The bioaccumulation potential of chemical substances is commonly determined in flow-through fish tests according to the Organization for Economic Cooperation and Development (OECD) technical guideline (TG) 305, aiming at the determination of bioconcentration factors (BCF). Investigations on aquatic organisms have shown a significant positive correlation between the accumulation of a chemical and the lipid content of organisms. Residue levels can thus differ between individuals, species, and size groups depending on their lipid content. BCF values can be normalized by lipid content; however, this requires the use of appropriate extraction techniques to ensure the complete extraction of total lipids from fish/tissue samples. The OECD TG 305 is currently under revision. A literature review was carried out to select preferred methods which shall be included in the updated OECD TG 305 along with a sampling schedule for lipid measurement in fish. Results: An overview and appraisal of a broad range of lipid extraction methods is presented. Extraction procedures applied in bioaccumulation studies described in the literature and procedures currently used for such studies by governmental, academic, and industrial labs are surveyed. Possible impacts of unsuitable extraction techniques on lipid normalized BCF results were assessed. Default values for BCF normalization commonly used in bioaccumulation studies are described. The effect of differences in residue distribution over different organs and/or lipids on the normalization of BCF values is discussed. Conclusions: A broad range of procedures for lipid extraction are available. However, only the use of suitable extraction techniques guarantees the complete extraction of total lipids from fish samples in bioaccumulation studies which is required to ensure the correct lipid normalization of BCF values. Preferred methods for inclusion in the updated OECD 305 test guideline as well as a standard schedule for lipid measurements are suggested.

Consistency in Trophic Magnification Factors of Cyclic Methyl Siloxanes in Pelagic Freshwater Food Webs Leading to Brown Trout

“…The extraction of total lipids by cyclohexane and isopropanol followed the recommended method for the revised OECD 305 guideline for determination of bioconcentration factor in fish, 26 with results well within the acceptable criteria for the Quasimeme ringtest for lipid determination (Supporting Information Table S9). …”

Emamectin benzoate: Potential larvicide and antifeedant agent against cotton Boll worm Helicoverpa armigera (Lepidoptera: Noctuidae)

“…Fourteen populations from Northern China have shown to possess 43-fold to 830-fold resistance to fenvalerate (Yang et al, 2013). Moreover, the tendency of insecticides to accumulate in lipids has increased the human health risks by their amplification in aquatic food chains (Schlechtriem et al, 2012). To alleviate the problem developed due to the overdependence on conventional insecticides in pest control programs, various groups of insecticides of natural origin have been synthesized with specific and selective action against desired species; and found to be safer for natural enemies and environment (Dhadialla et al, 1998;Thompson et al, 2000;Ignacimuthu and Jayaraj, 2003;Smagghe et al, 2003).…”

Comparison of laboratory‐derived biomagnification factors for hexachlorobenzene in common carp conducted under 9 test conditions

“…The value of the 5% lipid-normalized BMF kg did not differ markedly between the tests conducted using food with different lipid contents: tests A (0. In the aqueous exposure bioconcentration fish test [7], normalization of BCF values to lipid content is one way to reduce variability when comparing measured BCF values, for instance, for different species or animals of different life stages [22]. In the aqueous exposure bioconcentration fish test [7], normalization of BCF values to lipid content is one way to reduce variability when comparing measured BCF values, for instance, for different species or animals of different life stages [22].…”