Orion Research, Inc.

Other

Orion Research Puerto Rico, Inc.

James W Ross, Jr

Albert A Diggens

Steven J West

Edward E Bromberg

Martin S Frant

John H Riseman

Lionel S Goldring

Charles S Baer

Charles E Amass

Martin H Thomae

John C Synnott

An ion-chromatography system for analyzing one or more ionic species of a given polarity in solution, the system comprising an ion-exchange material reactive with such species, an eluant fluid, means for adding the eluant fluid and ionic species to the separation column, a stripper column and a detector. The eluant fluid includes at least a pair of electrically neutral molecular species reactive with one another to provide ionic constituents, the molecular species being in substantial equilibrium with the ionic constituents. The stripper column is positioned at the outlet of the separation column to receive the eluant fluid from the latter and reduce the concentration of the ionic constituents in the eluant fluid. The stripper column includes a conduit relatively permeable to the neutral molecular species in the eluant and relatively impermeable to the ionic constituents. Means are also provided for removing any of the neutral species that permeate the conduit, whereby a concentration gradient is established across the conduit. The detector is provided to quantitatively measure the chromatographically separated ionic species in the eluant discharged from the stripper column.

Method of and apparatus for chromatographic analysis

Apparatus for calibrating an ion analyzer comprises a calibration cell having defined therein a first volume for measuring an ion concentration of a sample when the instrument is operated in a monitoring and a second volume for measuring the ion concentration when the instrument is operated in a calibration mode. The first volume is included in, and forms part of, the second volume so that the matrix for the calibration measurement is essentially identical to that for the sample measurement. A double known-addition is used during the calibration mode to determine the calibration parameters.

Ion analyzer calibration cell

A potentiometric electrode having an ion selective half cell containing a non-reactive lead such as platinum in contact with an electrolyte containing a reversible redox couple having a large exchange current and a substantially flat temperature coefficient of potential such as 5 molar iodide, 3.times.10.sup.-2 molar triiodide, thereby having an electrode with a rapid and reproducible temperature response.

Temperature insensitive potentiometric electrode system

An improved flow independent method for electrochemical monitoring of a sample stream for the total concentration of a series of ionic species of the form X.sup.-n, H.sub.m X.sup.-n+m where n varies from 1 to m and X.sup.-n is an anion selected from the group consisting of fluoride ion, F.sup.-, and sulfide ion S.sup.-2. The pH of the sample stream is adjusted to a value below the pk.sub.a of the neutral most protonated species of the series. A first electrode sensitive to the activity of X.sup.-n is placed in the adjusted stream. The electric potential developed thereby is measured. A second electrode sensitive to the activity of hydrogen ion H.sup.+ is also placed in the adjusted stream. The electric potential developed thereby is also measured. The potential difference between the first and second electrode is a measure of the total concentration of the series X.sup.-n, H.sub.m X.sup.-n+m.

Electrochemical monitoring

An electrode sensitive to halide ion X.sup.- in solution, the ion-sensitive portion being an imporous membrane of a solid amalgam, such as gold and mercury, in combination with a finely divided salt of mercurous and halide ion X.sup.-, e.g. of the form Hg.sub.2 Cl.sub.2.

Halide electrode

An improved electrochemical reference electrode for use in potentiometric determinations of species in solution. The body of the electrode is composed of a material substantially permeable to liquid water whose exterior surface, excepting a comparatively small area, is covered by a membrane through which water may pass only by diffusion and which is also ion impermeable. The small area which is not covered forms an opening through the membrane to the body. The body contains a saturated salt slurry. When the electrode is immersed in an aqueous sample solution, water diffuses through the membrane and is transported in bulk across the body. Upon entry into the slurry, the water dissolves the solid salt in the slurry to produce an electrolyte which in turn flows outward through the small area of the body which is not covered by the membrane, whereby a liquid junction is provided between the electrolyte and the sample solution.

Reference electrode

An ammonia electrode having an internal standard electrolyte solution comprising a saturated aqueous solution of 5,5'-Nitrilodibarbituric acid ammonium salt.

Internal standard electrolyte for ammonia sensor

A method of monitoring the total residual chlorine in solution. A sample stream is extracted from the solution and mixed with a reagent stream containing a dissociated complex of alkali metal ion and iodide ion, and an excess amount of iodide ion. Iodide ion reacts with all the residual chlorine in the sample stream and is converted to iodine. The activity of iodine is then measured in the resultant mixed stream with a first and second electrochemical potentiometric electrode, the first electrode having a noble metal oxidation-reduction element, and the second having an iodide sensitive membrane element. The total residual chlorine is determined from the activity of the iodine.

Growing community of inventors

Cambridge, MA, United States of America

James W Ross, Jr