A device and method for determining the concentration of dicyanoaurate anions in a solution is disclosed. The device includes a semipermeable membrane formed from a material permeable to dicyanoaurate anions. The material may be comprised of an organopolysiloxane-polycarbonate block copolymer and a complexed salt of the dicyanoaurate anion.

A miniature probe contains a multifunctional electrochemical sensor which measures both the hydrogen ion activity or pH of samples and the carbon dioxide activity of samples. The miniature probe includes a carbon dioxide sensor. When the potential of one electrode in the probe is measured with respect to that of an external reference electrode, a pH sensor is provided.

A miniature probe contains multifunctional electrochemical electrodes which measure both specific ion activities of samples and the carbon dioxide or oxygen activity of samples. The miniature probe includes a carbon dioxide sensor or an oxygen sensor. When the specific ion electrode of the probe is connected to an external reference electrode, a specific ion sensor is provided.

A carton comprises opposite normally flat side panels, a normally flat transverse panel joined to the side panels along one edge of each of the side panels, an upper spout edge which is closed along a line cut across the transverse panel and angled downwardly in the side panels to first opposed flexure points in the side panels, a lower spout edge scored across the transverse panel, below the upper spout edge and angled upwardly in the side panels to the first flexure points, the lower spout edge intersecting each said edge of the side panels at said flexure points, and a score line extending from each of the first flexure points angularly downwardly to third flexure points at each said edge of the side panels below the second flexure points, the transverse panel thus providing, between the third flexure points and the lower spout edge, a trigger surface that can be pressed to swing inwardly of the carton about the third flexure points, forcing the lower spout edge and the second flexure points inwardly, and the side panels to bulge outwardly at the first flexure points, until the second flexure points lie in a common plane with the other flexure points, after which further inward movement of the trigger panel is assisted by pressure from the outwardly bulged side panels, whereby the second flexure points are urged farther inwardly and the upper spout edge is urged to extend outwardly by the pressure from the bulged side panels and the spout is held open. A carton blank is adapted to be erected into a such carton having an openable and recloseable pouring spout.

A one-piece disposable electrode comprising a sealed chamber containing an electrolyte solution, silver-silver chloride conductor in the electrolyte solution in the chamber and a cast-in-place membrane essentially flush with an exterior wall of this chamber for exposure to a biological fluid whose ion content is to be measured.