US 4,174,202 A · Kit and method for testing liquids for hydrogen sulfide content

Abstract

A method for quickly determining whether or not the H.sub.2 S concentration in fluids exceeds a preselected level, such as that set by government standards for oil field fluids, comprises: (1) admixing a preselected quantity of a liquid to be tested with a quantity of metal ion (such as Cd.sup.++) capable of reacting with sulfide ion to form a precipitate, the quantity of metal ion being equal to that required to precipitate a preselected amount of sulfide ion; (2) purging any residual H.sub.2 S from the liquid (such as by generating CO.sub.2 in situ); (3) contacting a reagent colorimetrically and selectively responsive to the presence of H.sub.2 S (such as lead acetate) with gas purged from the liquid; and (4) observing the color of colorimetrically responsive reagent. A kit convenient for use in carrying out the method in the field comprises: a capped bottle containing a premeasured quantity of a reagent reactable with hydrogen sulfide to form a precipitate; a second cap for the bottle, the second cap having mounted on at least a portion of its inner face a water-absorbent paper or fabric which serves as the substrate for the colorimetrically responsive reagent; an effervescent alkali metal bicarbonate tablet which is chargeable to the bottle; a second bottle containing the colorimetrically reactive reagent, said reagent bottle being normally closed, and means for transferring a portion of the colorimetrically responsive reagent to the water-absorbent substrate on the second cap.

Claims17

Dependent claims

A method for qualitatively determining whether or not a liquid contains hydrogen sulfide in a concentration in excess of a preselected concentration, which comprises, in sequence:

(a) admixing a preselected quantity of the liquid to be tested with a quantity of a metal cation capable of reacting with sulfide ion to form a precipitate, which quantity of cation is stoichiometrically sufficient to react with the hydrogen sulfide which would be present in said preselected quantity of liquid if said hydrogen sulfide were initially present at said preselected concentration;
(b) purging the liquid with an inert gas to remove unreacted hydrogen sulfide from the liquid;
(c) contacting a reagent colorimetrically and selectively responsive to the presence of hydrogen sulfide with the gas purged from the liquid;
(d) observing the color of the colorimetrically responsive agent, a color change in response to hydrogen sulfide being indicative that the liquid tested contained hydrogen sulfide at a concentration in excess of said preselected concentration.

1 more element

A test kit for qualitatively analyzing a sample of liquid to determine whether said liquid contains hydrogen sulfide in excess of a preselected concentration, which comprises:

(a) at least one reaction vial having an opening sealably closeable by a lid means and containing means for removing a quantity of hydrogen sulfide from a sample of liquid, said removal means comprising a preselected stoichiometric quantity of reagent in aqueous solution said reagent being reactable with said preselected concentration of hydrogen sulfide to form a precipitate;
(b) at least one first lid means sealably but removably closing said vial opening;
(c) at least one second lid means adaptable for sealably but removably closing said vial opening upon removal of said first lid means, said second lid having an inner face in fluid communication with the interior of said vial when said lid sealably closes the vial, and, mounted on at least a portion of said inner face, a water-absorbent paper or fabric adapted to support an indicating means;
(d) at least one means for generating an inert gas, comprising an effervescent alkali metal bicarbonate tablet chargeable to said reaction vial via said opening upon removal of said first lid means;
(e) a reservoir vial having an opening and containing means for indicating the presence of hydrogen sulfide, said indicating means comprising an aqueous solution of a reagent colorimetrically and selectively reactive with hydrogen sulfide, said opening being normally closed by means for closing said opening;
and
(f) means for transferring a portion of said indicating means from said reservoir vial to said water-absorbent paper or fabric.

4 more elements

Dependencies are inferred from the claim text.

Kit and method for testing liquids for hydrogen sulfide content

Life of this patent

Kit and method for testing liquids for hydrogen sulfide content

Life of this patent

Abstract

Claims17