US 11,988,608 B2
Method for determining the presence of an acidic sulfide species in a non-aqueous liquid using a metal complex dye
Philip Maltas, Ellesmere Port (GB)
Assigned to INNOSPEC LIMITED, Ellesmere Port (GB)
Appl. No. 16/633,349
Filed by INNOSPEC LIMITED, Ellesmere Port (GB)
PCT Filed Aug. 6, 2018, PCT No. PCT/GB2018/052245
§ 371(c)(1), (2) Date Jan. 23, 2020,
PCT Pub. No. WO2019/034844, PCT Pub. Date Feb. 21, 2019.
Claims priority of application No. 1713017 (GB), filed on Aug. 14, 2017.
Prior Publication US 2021/0156806 A1, May 27, 2021
Int. Cl. G01N 21/78 (2006.01); G01N 21/27 (2006.01); G01N 21/29 (2006.01); G01N 33/28 (2006.01)
CPC G01N 21/78 (2013.01) [G01N 21/272 (2013.01); G01N 21/293 (2013.01); G01N 33/2823 (2013.01); G01N 33/287 (2013.01)] 15 Claims
OG exemplary drawing
 
1. A method for determining presence of an acidic sulfide species in a non-aqueous liquid sample of an industrial or environmental material, the method comprising the steps of:
(a1) contacting the non-aqueous liquid sample with an extraction composition to form an aqueous phase and a non-aqueous phase, separating the aqueous and non-aqueous phases and collecting the aqueous phase or a portion thereof to provide an aqueous extract;
(a2) contacting the aqueous extract with a liquid composition comprising a metal complex dye compound thereby forming a mixture; and
(b) examining an electromagnetic absorption spectrum of the mixture obtained in step (a2) thereby quantitatively assessing whether any acidic sulfide species are present in the non-aqueous liquid sample,
wherein the electromagnetic absorption spectrum of the metal complex dye compound changes upon reaction with an acidic sulfide species;
wherein the industrial or environmental material are:
fluids in or extracted from an oil well;
products, by-products, intermediates, and waste streams from refineries and other industries;
and
wherein the metal complex dye compound is a copper complex of an azo dye; and
wherein the extraction composition includes a basic aqueous component having a pH of at least 10.