Inorganic carbon removal through acidification is a common practice prior to isotopic analysis of macroinvertebrate samples. We have experimentally tested the effect of acidification on the elemental and isotopic composition of a range of beach arthropod species. Acidification resulted in a significant depletion of 7.7% and 1.2% on average for carbon and nitrogen, respectively, suggesting that acid washing affects body carbon compounds other than carbonates. With a few exceptions, d13C and d15N showed no changes following 1 N HCl attack. Based on those exceptions, our results show that only those samples with a high CaCO3 content result in impoverished 13C as a consequence of acidification. Those suspected to be carbonate-free are not significantly affected. Concerning d15N values, only high carbonate species were affected when treated with HCl. As a standard protocol, it is recommended to acidify only carbonate-rich samples prior to d13C analyses. When possible, muscle tissue samples should be used instead of the entire organism.
Acid washing effect on elemental and isotopic composition of whole beach arthropods: Implications for food web studies using stable isotopes
Chelazzi L;
2008
Abstract
Inorganic carbon removal through acidification is a common practice prior to isotopic analysis of macroinvertebrate samples. We have experimentally tested the effect of acidification on the elemental and isotopic composition of a range of beach arthropod species. Acidification resulted in a significant depletion of 7.7% and 1.2% on average for carbon and nitrogen, respectively, suggesting that acid washing affects body carbon compounds other than carbonates. With a few exceptions, d13C and d15N showed no changes following 1 N HCl attack. Based on those exceptions, our results show that only those samples with a high CaCO3 content result in impoverished 13C as a consequence of acidification. Those suspected to be carbonate-free are not significantly affected. Concerning d15N values, only high carbonate species were affected when treated with HCl. As a standard protocol, it is recommended to acidify only carbonate-rich samples prior to d13C analyses. When possible, muscle tissue samples should be used instead of the entire organism.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.