Chemically integrating dosimeter and gas analysis methods

Claim 2

Method for detecting hydrogen sulfide gas by chemical integration comprising the steps of: providing a gas permeable, liquid impermeable outer membrane in conjunction with a liquid impermeable microporous hydrophobic inner membrane, the latter with a gas permeation rate substantially greater than that of the outer membrane; placing an internal electrolyte solution containing silver ions in contact with the inner membrane; allowing hydrogen sulfide gas to diffuse through the outer membrane, through the inner membrane, and into the internal electrolyte where the outer membrane is a gas permeation rate controlling membrane, and the inner membrane is a protective membrane; reacting the internal electrolyte with hydrogen sulfide gas to completely absorb said gas and to alter the composition of the internal electrolyte; and measuring the change in the concentration of silver ions in the electrolyte due to the entry of hydrogen sulfide gas into the internal electrolyte, whereby the concentration of the gas is determined.

Claim 3

The method of claim 1 wherein the internal electrolyte contains a silver ion concentration buffered with a silver complexing agent.

Claim 4

The method of claim 2 wherein the number of moles of Ag + ion in the internal electrolyte is in the range between two and four times the number of moles of the highest level of H 2 S to be detected, said highest level to be four times the threshold limit value of 10 ppm.

Claim 5

The method of claim 2 wherein the internal electrolyte is 7×10 -4 M AgNO 3 .

Claim 6

The method of claim 2 wherein the silver complexing agent is Na 4 EDTA.

Claim 7

The method of claim 5 wherein the concentration of Na 4 EDTA is 1 M.

Claim 8

The method of claim 2, wherein the silver complexing agent is a solution in a concentration which maintains a free silver activity in the electrolyte between 10 -6 and 10 -17 .

Claim 9

The method of claim 1 wherein the outer membrane is silicone polycarbonate copolymer.

Claim 10

The method of claim 1 wherein the inner membrane is microporous polytetrafluoroethylene.

Claim 11

The method of claim 1 wherein the outer membrane is silicone rubber.

Claim 12

The method of claim 1 wherein the inner membrane is microporous polyvinylchloride.

Claim 13

The method of claim 1 wherein the inner membrane is microporous polyvinylfluoride.

Claim 14

The method of claim 1 wherein the inner membrane is polypropylene.

Claim 15

The method of claim 1 wherein the inner membrane is microporous polyethylene.

Claim 16

A chemically integrating dosimeter for measuring hydrogen sulfide gas in the atmosphere comprising: a structural base, open on one side, for housing a solution; an internal electrolyte solution containing silver ions and a complexing agent, placed in the structural base so that upon absorption of H 2 S gas into the electrolyte a chemical reaction occurs within the electrolyte causing a change in silver ion concentration; a gas permeable, liquid impermeable gas permeation rate-controlling outer membrane with a permeation rate for H 2 S gas substantially lower than the diffusion rate of H 2 S gas in air, placed to cover the opening in the structural base; a microporous hydrophobic inner membrane substantially more permeable to gases than the outer membrane, impermeable to the internal electrolyte, and interposed between the internal electrolyte solution and the outer membrane to prevent chemical attack on the outer membrane by the electrolyte and to prevent precipitate deposition from the electrolyte on the outer membrane; means to seal the inner membrane and the outer membrane to the structural base; and means to measure the change in concentration of silver ions Ag + in the internal electrolyte.

Claim 17

A chemically integrating dosimeter for measuring hydrogen sulfide gas in the atmosphere comprising: a structural base, open on one side, for housing a solution; an internal electrolyte solution containing silver ions and a complexing agent, placed in the structural base so that upon absorption of H 2 S gas into the electrolyte a chemical reaction occurs within the electrolyte causing a change in silver ion concentration; a gas permeable, liquid impermeable gas permeation rate-controlling outer membrane with a permeation rate for H 2 S gas substantially lower than the diffusion rate of H 2 S gas in air, placed to cover the opening in the structural base; a microporous hydrophobic inner membrane substantially more permeable to gases than the outer membrane, impermeable to the internal electrolyte, and interposed between the internal electrolyte solution and the outer membrane to prevent chemical attack on the outer membrane by the electrolyte and to prevent precipitate deposition from the electrolyte on the outer membrane; means to seal the inner membrane and the outer membrane to the structural base; and means to measure the change in concentration of silver ions Ag + in the internal electrolyte.

Claim 18

The dosimeter of claim 15 wherein the outer membrane is silicone rubber.

Claim 19

The dosimeter of claim 15 wherein the outer membrane is silicone polycarbonate copolymer.

Claim 20

The dosimeter of claim 15 wherein the inner membrane is microporous polytetrafluoroethylene.

Claim 21

The dosimeter of claim 15 wherein the inner membrane is microporous polyvinylchloride.

Claim 22

The dosimeter of claim 15 wherein the inner membrane is microporous polyethylene.

Claim 23

The dosimeter of claim 15 wherein the inner membrane is microporous polyvinylfluoride.

Claim 24

The dosimeter of claim 15 wherein the inner membrane is microporous polypropylene.

Claim 25

The dosimeter of claim 15 wherein the internal electrolyte is silver nitrate.

Claim 26

The dosimeter of claim 15 wherein the silver complexing agent is a solution in a concentration which maintains a free silver activity in the electrolyte between 10 -6 and 10 -17 .

Claim 27

The dosimeter of claim 15 wherein the silver complexing agent is Na 4 EDTA.

Claim 28

The dosimeter of claim 15 wherein the concentration of Na 4 EDTA is 1 M and the concentration of AgNO 3 is 7×10 -4 M.

Claim 29

A chemically integrating dosimeter for measuring sulfur dioxide gas in the atmosphere comprising: a structural base, open on one side, for housing a solution; an internal electrolyte solution containing bromide ion and mercuric bromide placed in the structural base so that upon absorption of SO 2 gas into the electrolyte a chemical reaction occurs within the electrolyte causing a change in bromide ion concentration; a gas permeable, liquid impermeable gas permeation rate-controlling outer membrane with a permeation rate for SO 2 gas substantially lower than the diffusion rate of SO 2 gas in air, placed to cover the opening in the structural base; a microporous hydrophobic inner membrane substantially more permeable to gases than the outer membrane, impermeable to the internal electrolyte, and interposed between the internal electrolyte solution and the outer membrane to prevent chemical attack on the outer membrane by the electrolyte and to prevent precipitate deposition from the electrolyte on the outer membrane; means to seal the inner membrane and the outer membrane to the structural base; and means to measure the change in concentration of bromide ions Br - in the internal electrolyte.

Claim 30

A chemically integrating dosimeter for measuring sulfur dioxide gas in the atmosphere comprising: a structural base, open on one side, for housing a solution; an internal electrolyte solution containing bromide ion and mercuric bromide placed in the structural base so that upon absorption of SO 2 gas into the electrolyte a chemical reaction occurs within the electrolyte causing a change in bromide ion concentration; a gas permeable, liquid impermeable gas permeation rate-controlling outer membrane with a permeation rate for SO 2 gas substantially lower than the diffusion rate of SO 2 gas in air, placed to cover the opening in the structural base; a microporous hydrophobic inner membrane substantially more permeable to gases than the outer membrane, impermeable to the internal electrolyte, and interposed between the internal electrolyte solution and the outer membrane to prevent chemical attack on the outer membrane by the electrolyte and to prevent precipitate deposition from the electrolyte on the outer membrane; means to seal the inner membrane and the outer membrane to the structural base; and means to measure the change in concentration of bromide ions Br - in the internal electrolyte.

Claim 31

The dosimeter of claim 27 wherein the outer membrane is silicone rubber.

Claim 32

The dosimeter of claim 27 wherein the outer membrane is silicone polycarbonate copolymer.

Claim 33

The dosimeter of claim 27 wherein the inner membrane is microporous polytetrafluoroethylene.

Claim 34

The dosimeter of claim 27 wherein the inner membrane is microporous polyvinylchloride.

Claim 35

The dosimeter of claim 27 wherein the inner membrane is microporous polyethylene.

Claim 36

The dosimeter of claim 27 wherein the inner membrane is microporous polyvinylfluoride.

Claim 37

The dosimeter of claim 27 wherein the inner membrane is polypropylene.

Claim 38

The dosimeter of claim 27 wherein the internal electrolyte contains an acetic acid buffer.

Claim 39

The dosimeter of claim 27 wherein the internal electrolyte contains dimethylformamide.

Claim 40

The dosimeter of claim 27 wherein the internal electrolyte solution is 1×10 -3 M mercuric bromide (HgBr 2 ) in 5×10 -3 M acetic acid buffer (HOAc/NaOAc) at pH 4.8 with 1% dimethylformamide.

Claim 41

Method for detecting sulfur dioxide gas by chemical integration comprising the steps of: providing a gas permeable, liquid impermeable outer membrane in conjunction with a liquid impermeable microporous hydrophobic inner membrane, the latter with a gas permeation rate substantially greater than that of the outer membrane; placing an internal electrolyte solution containing bromide ion and mercuric bromide in contact with the inner membrane; allowing sulfur dioxide gas to diffuse through the outer membrane, through the inner membrane, and into the internal electrolyte where the outer membrane is a gas permeation rate controlling membrane, and the inner membrane is a protective membrane; reacting the internal electrolyte with sulfur dioxide gas to completely absorb said gas and to alter the composition of the internal electrolyte; and measuring the change in the concentration of bromide ions in the electrolyte due to the entry of sulfur dioxide gas into the internal electrolyte, whereby the concentration of the gas is determined.

Claim 42

Method for detecting sulfur dioxide gas by chemical integration comprising the steps of: providing a gas permeable, liquid impermeable outer membrane in conjunction with a liquid impermeable microporous hydrophobic inner membrane, the latter with a gas permeation rate substantially greater than that of the outer membrane; placing an internal electrolyte solution containing bromide ion and mercuric bromide in contact with the inner membrane; allowing sulfur dioxide gas to diffuse through the outer membrane, through the inner membrane, and into the internal electrolyte where the outer membrane is a gas permeation rate controlling membrane, and the inner membrane is a protective membrane; reacting the internal electrolyte with sulfur dioxide gas to completely absorb said gas and to alter the composition of the internal electrolyte; and measuring the change in the concentration of bromide ions in the electrolyte due to the entry of sulfur dioxide gas into the internal electrolyte, whereby the concentration of the gas is determined.

Claim 43

The method of claim 38 wherein the outer membrane is silicone rubber.

Claim 44

The method of claim 38 wherein the outer membrane is silicone polycarbonate copolymer.

Claim 45

The method of claim 38 wherein the inner membrane is microporous polytetrafluoroethylene.

Claim 46

The method of claim 38 wherein the inner membrane is microporous polyvinylchloride.

Claim 47

The method of claim 38 wherein the inner membrane is microporous polyvinylfluoride.

Claim 48

The method of claim 38 wherein the inner membrane is polypropylene.

Claim 49

The method of claim 38 wherein the internal electrolyte contains an acetic acid buffer.

Claim 50

The method of claim 38 wherein the internal electrolyte contains dimethylformamide.

Claim 51

The method of claim 38 wherein the internal electrolyte solution is 1×10 -3 M mercuric bromide (HgBr 2 ) in 5×10 -3 M acetic acid buffer (HOAc/NaOAc) at pH 4.8 with 1% dimethylformamide.