Hydranal titrant 5

1-Ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C₂MIm][Tf₂N], purity: ≥98% NMR), 1-Butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C₄MIm][Tf₂N], purity: ≥98% HPLC) and 1-Hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C₆MIm][Tf₂N], purity: ≥98% HPLC) were purchased from Sigma-Aldrich. 1-Octyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C₈MIm][Tf₂N], purity: ≥99.9%) was purchased from Solvionic. For volumetric Karl-Fischer titration (TitraLab KF1000), HYDRANAL^®-Titrant 5 with a water equivalent of 4.95~5.05 mg/mL and HYDRANAL^®-solvent E (ethanol based) were purchased from Sigma-Aldrich.

The water content of β-CD/ASO complexes was determined by the bi-component technique of volumetric KFT. A KF 701 Titrino apparatus, equipped with a 10 mL dosing system and coupled with a 703 Ti Stand stirring system (both from Metrohm, Herisau, Switzerland) was used. A complex of up to 100 mg was used for KFT analysis. The bulk solvent volume (component 2, Hydranal-Solvent, Sigma-Aldrich) was 30 mL at the start of the analysis. Hydranal-Titrant 5 was used as component 1 (Sigma-Aldrich). The titer of the component 1 was determined by using Hydranal-Water Standard 10.0 mg H₂O·g⁻¹ (Sigma-Aldrich). An electrode polarization of 50 μA, endpoint voltage of 250 mV, maximum titration rate of 5 mL·min⁻¹, drift as stop criterion, a drift value of 20 μL·min⁻¹, and an extraction time of 300 s were the values for the main KFT parameters.

Atlantic salmon (Salmo salar L.) was obtained from the local market (Timişoara, Romania) as a raw product in the spring of 2014. It was an aquaculture product of Norwegian origin. Only the meaty fish parts were used for oil extraction. GC-grade hexane (Sigma-Aldrich) was the main solvent used for raw and degraded fish oil dilutions. The Supelco 37 Component FAME mix (Sigma-Aldrich) and C₈–C₂₀ alkane standard solution (Fluka Chemie AG) were the main tools for identifying the FAMEs in derivatized raw and degraded fish oil. Anhydrous sodium sulfate (p.a., Merck & Co.) was used for drying the raw and degraded fish oil solutions. β-CD hydrate (>98%) from CycloLab (Budapest, Hungary) was used for ASO molecular encapsulation. Ethanol 96% (v/v, Chimopar, Bucharest, Romania) was used for β-CD complexation of ASO. A boron trifluoride–methanol complex (20%, Merck & Co., Inc.) was used for FA derivatization. Finally, Hydranal-Titrant 5, Hydranal-Solvent and Hydranal-Water Standard 10.0 (Sigma-Aldrich, Buchs, Switzerland) were used for the KFT water analysis of β-CD/ASO complexes.