N hexane

Tetraethyl-orthosilicate (TEOS, reagent grade 98%; Merck), ethanol (≥ 99.5%, Ph.Eur., reinst; Roth) deionized water, hydrochloric acid (37%; Merck), and ammonium hydroxide solution in water (25%; Merck) were used as supplied. Furthermore, hexane (n-hexane, > 99%; Carl Roth) and trimethylchlorosilane (TMCS, purified by redistillation > 99%; Merck) were used as received.

Lipase B form Candida antarctica (lipozyme CalB) was a kind gift from Novozymes (Bagsværde, Denmark). CalB immo Plus was purchased from c-LEcta, Germany. Copper bromide, N,N,N′,N″,N″-pentamethyldiethylenetriamine, methyl methacrylate (MMA), 4-methylumbelliferyl butyrate, oleic acid (88%), and tetramethyl orthosilicate were purchased from Sigma Aldrich/Merck (Darmstadt, Germany)). 3-Aminopropyltriethoxysilane and 3-(trimethoxysilyl)propyl 2-bromo-2-methylpropanoate were from abcr (Karlsruhe, Germany). Acetonitrile, ascorbic acid, anisole, ethanol (abs.), glutaraldehyde (25%), isopropyl alcohol, methanol, n-hexane, tetrahydrofuran (THF), and pyridine were from Carl Roth (Karlsruhe, Germany). MMA was purified using an aluminum oxide column followed by distillation before polymerization and isopropyl alcohol was dried with molecular sieves. All other chemicals were used as received.

For PUFA analysis, approximately 100 mg tissue samples were homogenized in liquid nitrogen using a biopulverizer. Total fatty acids were extracted using a modified Morisson and Smith procedure as previously described [22 (link),23 (link)], allowing for direct one-step transesterification of total fatty acids in tissue homogenates: An aliquot of each tissue homogenate was subjected to fatty acid methylation with 500 μL n-hexane (Carl Roth, Karlsruhe, Germany), 500 μL 12% boron trifluoride-methanol solution (Sigma-Aldrich, Steinheim, Germany) and 50 μL pentadecanoic acid (1 mg/mL; Sigma-Aldrich) as internal standard and incubated for 60 min at 100 °C. After cooling down to room temperature, fatty acid methyl esters were extracted in the hexane phase following the addition of 750 μL H₂O. The samples were vortexed for 4 min and centrifuged (5 min, 3500 rpm). The upper hexane phase was removed and stored at −20°C until analysis.

n-Pentane (>99%), n-hexane (>99%), and 2-methyltetrahydrofuran (2-MTHF, >99%) were obtained from Carl Roth, and furfural (>98%) was obtained from Alfa Aesar. All chemicals were used without further purification. Beech wood (Fagus sp.) was obtained from local suppliers; the particle size was generated by a cutting mill with a 10 mm sieve and dried at 50 °C until weight constancy (ca. 24 h), leaving a residual moisture content of approx. 10% water.

The experiments have been done with spherical
SiO₂ (SFP-20M from Denka, Japan), spherical Al₂O₃ (ASFP-20 from Denka, Japan), and nonspherical SnO₂ (from Carl Roth, Germany, >99.5%) shown in Figure 3. ZnCl₂ (from Merck,
Germany, >99.0%) and MgCl₂ (from Carl Roth, Germany,
>99.0%)
have been used for the charge reversal. The used surfactant SDS was
obtained from Carl Roth, Germany, with a purity of >99.0%. n-Hexane (from Carl Roth, Germany, >99.0%) has been used
for phase transfer experiments. The chemicals used in the experiments
have been used without further purification. Only SnO₂ was
purified with the following procedure: First, the SnO₂ was
dispersed in an 1 mmol/L NaCl solution, followed by the dispersion
in Milli-Q water three times. All solutions and suspensions were
made with Milli-Q water. While using Milli-Q water, care was taken
to ensure that the conductivity value did not exceed 0.055 μS/cm
and a TOC of 2 ppb.
The metal oxides used are model systems selected
to investigate
the adsorption of the different salts (ZnCl₂ and MgCl₂). When selecting the materials, it was important that they
had different IEPs as shown in Figure 5.

Acetic acid and methanol (Optima LC/MS Grade) as well as acetonitrile (HPLC-MS grade) were obtained from Fisher Scientific (Schwerte, Germany) and ammonium acetate (p.a.) was purchased from Merck (Darmstadt, Germany). Methyl tert-butyl ether and n-hexane (HPLC grade) were obtained from Carl Roth (Karlsruhe, Germany). Methyl tricosanoate (FAME C23:0) was obtained from Santa Cruz Biotechnology (Heidelberg, Germany). Oxylipin and deuterated oxylipin standards were purchased from Cayman Chemicals (local distributor: Biomol, Hamburg, Germany). Further oxylipin standards (Epoxy octadecadienoic acids (EpODEs) and dihydroxy octadecadienoic acids (DiHODEs)) were a kind gift from the laboratory of Bruce Hammock (UC Davis, CA, USA). Ethyl acetate, methyl formate and all other chemicals were purchased from Sigma Aldrich (Taufkirchen, Germany).