Abstract: A method of making an electroanalytical measurement including providing a glass-fused working electrode that includes a tungsten rod and a glass coating fused to the rod to form a leak-proof seal, which defines a fixed working electrode area; inserting the electrode into a molten salt such that the fixed working electrode area is completely submerged and a portion of the glass coating is in contact with the molten salt; applying a potential to the molten salt; measuring current as a function of potential; and quantifying a concentration of an analyte.