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The determination of fatty acids by nonaqueous CZE with capacitively coupled contactless conductivity detection was investigated. A new deoxycholate-based BGE, which had previously been found to give significantly improved baseline stability in the determination of lipophilic organic ammonium ions, was found to be similarly beneficial for the determination of the anions. The use of a PVA-coated capillary was required for suppression of the EOF and to obtain well reproducible results. The complete separation of 12 fatty acids could be achieved with 10 mM DOC in methanol within 6 min under optimized conditions. The PVA-coated capillary demonstrated outstanding stability over 300 runs with no sign of depletion of the PVA layer. Method validation showed a good linearity range from 0.75 to 25 μM with correlation coefficients between 0.9949 and 0.9979. The LOD was determined as 0.5 μM for all fatty acids. The developed approach was successfully demonstrated for the separation of free fatty acids in commercial and home-made edible oil.

Graphene has great potential in electrochemical storage applications for supercapacitors owing to its high conductivity, large surface area, and the economical feasibility in producing it. The main issue that faces graphene nanomaterials in this application is that they tend to restack, thus decreasing the accessible surface area and leading to low capacitance. Gold nanoparticles of various sizes (2–150 nm) can be used as efficient spacing material for electrochemically reduced graphene oxide, thereby greatly increasing capacitance from 4.99 F g−1, when no spacers are used, to a capacitance of 174.2 F g−1 (per gram of graphene) when gold nanospacers of 10 nm diameter are introduced.