title: Drying method has no substantial effect on δ(15)N or δ(13)C values of muscle tissue from teleost fishes.
abstract: BACKGROUND
  Stable isotope analysis (SIA) is a powerful tool in many fields of research that enables quantitative comparisons among studies, if similar methods have been used. The goal of this study was to determine if three different drying methods commonly used to prepare samples for SIA yielded different δ(15)N and δ(13)C values.
  
  
  METHODS
  Muscle subsamples from 10 individuals each of three teleost species were dried using three methods: (i) oven, (ii) food dehydrator, and (iii) freeze-dryer. All subsamples were analysed for δ(15)N and δ(13)C values, and nitrogen and carbon content, using a continuous flow system consisting of a Delta V Plus mass spectrometer and a Flush 1112 elemental analyser via a Conflo IV universal interface. The δ(13)C values were normalized to constant lipid content using the equations proposed by McConnaughey and McRoy.
  
  
  RESULTS
  Although statistically significant, the differences in δ(15)N values between the drying methods were small (mean differences ≤0.21‰). The differences in δ(13)C values between the drying methods were not statistically significant, and normalising the δ(13)C values to constant lipid content reduced the mean differences for all treatments to ≤0.65‰. A statistically significant difference of ~2% in C content existed between tissues dried in a food dehydrator and those dried in a freeze-dryer for two fish species. There was no significant effect of fish size on the differences between methods.
  
  
  CONCLUSIONS
  No substantial effect of drying method was found on the δ(15)N or δ(13)C values of teleost muscle tissue.
authors.affiliation: Florida International University, Department of Biological Sciences, Marine Science Program, 3000 N.E. 151 Street, North Miami, FL, 33181, USA.
authors.forename: Cindy
authors.initials: C
authors.lastname: Bessey
authors.forename: Mathew A
authors.initials: MA
authors.lastname: Vanderklift
mesh_terms: D000818:Animals; D002247:Carbon Isotopes / Q000032:analysis*; D003890:Desiccation / Q000379:methods*; D005399:Fishes; D005612:Freeze Drying / Q000379:methods*; D016014:Linear Models; D013058:Mass Spectrometry; D009132:Muscles / Q000737:chemistry*; D009587:Nitrogen Isotopes / Q000032:analysis*; D015203:Reproducibility of Results
chemical_list: D002247:Carbon Isotopes; D009587:Nitrogen Isotopes