Effects of chemical pretreatment and intra- and inter-specimen variability on δ18O of aquatic insect remains

Oxygen isotope (δ18O) measurements on the exoskeletons of aquatic insects can be used to reconstruct changes in the δ18O of ambient water and, indirectly, to infer the climate and environmental conditions at the time of tissue synthesis. Prior to stable isotope analysis, it is often necessary to chemically pretreat insect remains to remove allochthonous organic and inorganic compounds without altering the δ18O signature. We tested the...