Abstract: Colorimetric indicators for breath, air, gas, & vapor analyses that can be thrown away after a single use, are easy to use, low cost, small, and simple to manufacture for indicating at least volume passed through the colorimetric indicators and may also be used to indicate concentration of an analyte within breath, air, gas, & vapor passed through the colorimetric indicators. The present invention is directed to colorimetric indicators for breath, air, gas, & vapor analyses. The colorimetric indicators may have a housing with an entrance port, an outlet, a volume indicator, and an analyte indicating reagent. The volume indicator may be a breath volume reagent. Different analytes may be measured, the analyte indicating reagent depending upon the particular analyte being to monitored. The breath volume indicator is colorimetric, and changes color when a predetermined volume of air is passed through the colorimetric indicators for breath, air, gas, & vapor analyses.

Abstract: Apparatus and methods for quickly and easily detecting trace amounts of metallic or non-metallic, electro-active substances, and in particular trace amounts of metals, such as lead in a portable, hand-held detector system with single potential control.

Abstract: Oxygen is extracted from a fluid mixture feedstock by circulating a carrier fluid from an oxygen loading station to an electrochemical cell. The carrier fluid includes a carrier compound capable of reversibly binding oxygen, with oxygen binding dependent on the oxidation state of the compound. Oxygen bound to the carrier compound in a first oxidation state is released as the oxidation state is altered at the first electrode of the electrochemical cell. The carrier compound is then returned to the first oxidation state at the second electrode at the electrochemical cell. The loading station typically comprises an oxygen-permeable membrane which prevents bulk mixing of the fluid mixture and the carrier fluid.

Abstract: Methods and apparatus for the extraction of a ligand such as molecular oxygen from a first fluid environment and for release of a ligand such as molecular oxygen, as well as ligand carrier compounds therefor comprising linear, pentadentate polyalkylamines and transition metal ions. The carrier compounds have the general formula: ##STR1## where, each of R.sub.1 and R.sub.2 is independently an organic group including a sulfur, an oxygen or a nitrogen coordinated to M;each of m, n, o, and p is 1, 2, 3, or 4;X is selected from the group consisting of 2,6-pyridyl, 2,6-piperidyl, 2,5-pyrrolyl, 2,4-imidazolyl, substituted heterocyclic amines, --)--, --S--, ##STR2## and ##STR3## where R.sub.3 is hydrogen, lower alkyl or aralkyl; and M is a transition metal ion.