325 results about "Hydrogen-Ion Concentrations" patented technology

Methods and apparatus relating to very large scale FET arrays for analyte measurements. ChemFET (e.g., ISFET) arrays may be fabricated using conventional CMOS processing techniques based on improved FET pixel and array designs that increase measurement sensitivity and accuracy, and at the same time facilitate significantly small pixel sizes and dense arrays. Improved array control techniques provide for rapid data acquisition from large and dense arrays. Such arrays may be employed to detect a presence and / or concentration changes of various analyte types in a wide variety of chemical and / or biological processes. In one example, chemFET arrays facilitate DNA sequencing techniques based on monitoring changes in hydrogen ion concentration (pH), changes in other analyte concentration, and / or binding events associated with chemical processes relating to DNA synthesis.

A cellulose acetate solution is filtrated with a filter medium formed of cellulose fiber. Hydroxyl groups on the filter medium are substituted to other functional groups. An acidic material is added to the cellulose acetate solution, and the filtration is preformed. In order to estimate the hydrogen ion concentration of the organic solvent, a sample solvent of thereof is mixed with water so as to transport hydrogen ions from the sample solvent to the water of a predetermined volume. Then the water is separated from the sample solvent, and the pH value of the water is measured with a pH meter. The result of the measurement is regarded as the pH value of the organic solvent.

A method for producing a toner particle having high charging stability and durability under environments at high temperature and high humidity is provided.A method for producing a toner particle including an step of adhering a resin particle to surface of a toner base particle containing a binder resin and a colorant in an aqueous medium, wherein the resin particle contain a resin having an ionic functional group and having an acid dissociation constant pKa of 6.0 or more and 9.0 or less, and the pH (hydrogen ion concentration) of the aqueous medium is equal to or greater than pKa of the resin particle−2.0.

Particular aspects provide novel devices and methods for accurately measuring total ammonia (NH3 plus NH4+) in a solution (e.g., freshwater and saltwater) by spatially proximate, simultaneous and continuous quantitative measurement of solution pH and ammonia. The devices overcome prior art inaccuracies relating to non-homogeneous sampling, and to spatial, temporal and thermal sampling discontinuities. Particular embodiments provide a combination pH and ammonia measuring device, comprising: a submersible member; a submersible non-bleeding ammonia-sensing portion attached to the submersible member and suitable to provide for a continuous visual indicator of solution ammonia concentration; a submersible non-bleeding pH-sensing portion attached to the submersible member and suitable to provide for a continuous visual indicator of solution pH; visual ammonia and pH indicator comparison means suitable for comparative quantitative determination of solution ammonia concentration and pH. Additional aspects provide novel ultra-sensitive devices and methods using same for measuring ammonia in air or solution.

A transdermal medicament patch includes a biocompatible substrate having a therapeutic face on one side configured for disposition against the skin of a patient, a biocompatible adhesive on the therapeutic face, a planar medicament matrix covering a portion of the therapeutic face, and a release liner covering the portion of therapeutic that is not obscured by the medicament matrix. An aperture formed through the release sheet affords direct access by medicament to the entire surface of the medicament matrix opposite from the therapeutic face of the substrate. An active electrode positioned between the medicament matrix and the therapeutic face of the substrate includes an electrically conductive backing layer positioned against the therapeutic face of the substrate and a pH-control layer covering less than all of the side of the backing layer opposite from the therapeutic face of the substrate. One active electrode design criterion relates the relative size of the pH-control layer to the size of the backing layer; another relates the size of portion of the area of the backing layer that is free of the pH-control lawyer to the size of the pH-control layer. The pH-control layer is made of an electrically conductive material capable of moderating changes in the hydrogen-ion concentration in the medicament matrix during iontophoretic current flow. An electrical contact electrically coupled through the substrate to the backing layer includes a hollow, electrically conductive snap fitting having an open end and a cooperating stud that is inserted into the open end of the snap.