Abstract: An improved assay method and reagent composition for the determination of magnesium in a fluid sample by reaction with an alkaline buffered solution of calmagite, in which caffeine and preferably also thiourea have been included, thereby achieving parity between protein-free and protein-containing samples while eliminating the need for cyanide.

Abstract: A reference element for a catalytic gas sensor with improved life in the presence of combustible gases is described. The sensor comprises a filament such as a platinum-iridium alloy coated with a layer of titanium dioxide. The coating typically contains a high temperature stable inorganic binder such as aluminum oxide. The filament can be in coil-form pre-encased in a glass bead. Such sensor has long term stability in the presence of combustible organic gases such as alkenes, alkadienes, alkynes, and epoxide containing hydrocarbon gases, for example. Sensors containing such elements have particular utility in the area of mining and oil drilling environments, as well as industrial, safety, and commercial applications.

Abstract: An electrochemical detector cell (10) and apparatus incorporating the cell (10) includes a first capillary (12) having an entrance (14) connected to an electrolyte source (30) and an exit (16). A second capillary (18) is connected to reactive gas source (32) and intersects the first capillary (12) at (22) to define a reaction zone (20) in the first capillary (12). A sensor electrode (24) is positioned in the first capillary (12) in the reaction zone (20). A third capillary (26) intersects the first capillary (12) within the reaction zone (20). A reference electrode (28) is positioned in the third capillary (26). The third capillary (26) is connected to a solution source (34). The electrodes (24) and (28) may be used for potentiometric measurements. A fourth capillary (38) intersects the first capillary between entrance (14) and intersection (22) of the first capillary (12) and the second capillary (18).