Low-level boron detection and measurement
AssigneeSievers Instruments, Inc.
InventorsPaul P. Kosenka, Kevin J. O'Neill, Richard D. Godec
Life of this patent
Estimating the term…
Abstract
Methods and apparatus (50) are disclosed for accurately measuring low concentrations of boron in deionized water utilizing the chemical reaction of boric acid with a polyol by injecting very small plugs of concentrated polyol into streams of boron containing and non-boron containing water samples to produce an ionized acids product, and then measuring the conductivity difference (delta conductivity), corrected for interfering or extraneous factors which can effect conductivity, between such boron containing and non-boron containing samples using a conductivity and temperature detector (23).
Claims43
Apparatus for measurement of boron at very low concentration in water or other solvent comprising:
- (a) a source of a sample of said water or other solvent which may contain boron;
- (b) a source of a sample of said water or other solvent which is substantially free of boron;
- (c) a source of substantially intrinsic polyol solution, said polyol capable of forming a complex with boric acid and/or anions of boric acid;
- (d) a contacting system for:
- (i) contacting a portion of said intrinsic polyol solution intermittently with said sample of said water or other solvent which may contain boron thereby forming a first volume of liquid comprising said polyol and said water or solvent;
- and (ii) intermittently contacting a portion of said intrinsic polyol solution with said sample of said water or other solvent substantially free of boron thereby forming a second volume of liquid comprising said polyol and said water or other solvent substantially free of boron;
- (e) a conductance measuring unit for measuring electrical conductance of said first volume of liquid and, alternatively, of said second volume of liquid;
- and,
- (f) a correlating system for correlating boron concentration in said water or other solvent with said conductance of said first volume of liquid and said conductance of said second volume of liquid.
An apparatus according to 16 wherein said sample water delivery system comprises a sample water inlet;
- conduits for channeling a sample from said sample water inlet either through a boron-removing resin, or alternatively, so as to bypass said boron-removing resin;
- at least a valve for controlling whether said sample passes through or bypasses said boron-removing resin;
- and, a fluid conduit connecting said sample supply system to an input conduit of said injection system.
A method for measurement of boron at very low concentrations in water or other solvent, said method comprising providing an apparatus which comprises:
- (i) a source of a sample of said water or other solvent which may contain boron;
- (ii) a source of a sample of said water or other solvent which is substantially free of boron;
- (iii) a source of substantially intrinsic polyol solution, said polyol capable of forming a complex with boric acid and/or anions of boric acid;
- (iv) a contacting system for:
- (i) contacting a portion of said intrinsic polyol solution intermittently with said sample of said water or other solvent which may contain boron thereby forming a first volume of liquid comprising said polyol and said water or solvent;
- and (ii) intermittently contacting a portion of said intrinsic polyol solution with said sample of said water or other solvent substantially free of boron thereby forming a second volume of liquid comprising said polyol and said water or other solvent substantially free of boron;
- (v) a conductance measuring unit for measuring electrical conductance of said first volume of liquid and, alternatively, of said second volume of liquid;
- and,
- (vi) a correlating system for correlating boron concentration in said water or other solvent with said conductance of said first volume of liquid and said conductance of said second volume of liquid;
- said method comprising the further steps of:
- (a) providing a flowing sample of said water other solvent which may contain boron;
- (b) contacting a portion of said intrinsic polyol solution intermittently with said flowing sample which may contain boron to form said first volume of liquid;
- (c) measuring electrical conductance of said first volume of liquid;
- (d) intermittently providing a flowing sample of said water or other solvent which is substantially free of boron;
- (e) contacting a portion of said intrinsic polyol solution with said flowing sample which is substantially free of boron to form said second volume of liquid;
- (f) measuring electrical conductance of said second volume of liquid;
- and,
- (g) correlating boron concentration in said water or other solvent with the electrical conductance of said first volume off liquid and the electrical conductance of said second volume of liquid.
A method according to 21 further comprising the step of displaying and/or recording said correlated boron concentration.
A method for measurement of boron in an aqueous solution at a very low concentration of about 0.001 ppb to about 1000 ppb as boron comprising the steps of:
- (a) adding to a small aliquot injection of a polyol solution a boron containing sample water portion, and measuring conductance of the resulting polyol/boron sample water solution;
- (b) adding to a small aliquot injection of the polyol solution a substantially boron-free sample water portion, and measuring conductance of the resulting polyo/boron-free sample water solution;
- (c) determining a conductance differential based on the difference between the conductance of the polyol/boron-containing sample water solution and the conductance of the polyol/boron-free sample water solution;
- and (d) relating said conductance differential to the concentration of boron in the boron-containing sample water portion.
Dependencies are inferred from the claim text.