Method for rapidly determining sulfur content in a plurality of samples

Patent metadata

Field	Value
Publication number	US-10458964-B2
Application number	US-201715720669-A
Country	US
Kind code	B2
Filing date	Sep 29, 2017
Priority date	Sep 29, 2017
Publication date	Oct 29, 2019
Grant date	Oct 29, 2019

Abstract

Methods for measuring the sulfur content in a plurality of individual sulfur-containing fiber or article samples, comprising: a) contacting a plurality of samples with a solution comprising potassium hydroxide to convert the sulfur to potassium sulfate; b) concurrently and individually combusting the plurality of samples from step a) in a furnace at a temperature of greater than 650° C. to remove essentially all organic materials to produce a plurality of residues; c) dissolving each of the pluralities of residue in concentrated nitric acid to form individual residue solutions; and d) analyzing the individual residue solutions with Inductively Coupled Plasma (ICP) Emission Spectrometry to determine the sulfur content of each sample.

First claim

What is claimed:

1. A method of measuring the sulfur content in a plurality of individual sulfur-containing fiber or article samples, the method comprising the steps of:
a) contacting a plurality of sulfur-containing fiber or article samples with an aqueous solution comprising potassium hydroxide to convert the sulfur to potassium sulfate;
b) concurrently and individually combusting the plurality of samples from step a) in a furnace at a temperature of greater than 650° C. to remove essentially all organic materials and produce a plurality of residues;
c) dissolving each of the pluralities of residue in concentrated nitric acid to form individual residue solutions; and
d) analyzing the individual residue solutions with Inductively Coupled Plasma (ICP) Emission Spectrometry to determine the sulfur content of each sample.

2. The method of claim 1 , where said solution comprising potassium hydroxide is an aqueous solution having a potassium hydroxide content in the range of from 0.01 to 1 N.

3. The method of claim 1 wherein after step a) and prior to step b), the plurality of sulfur-containing samples of step a) are further heated to remove liquid from the samples.

4. The method of claim 2 wherein after step a) and prior to step b), the plurality of sulfur-containing samples of step a) are further heated to remove liquid from the samples.

Assignees

• Du Pont
• Dupont Safety & Construction Inc

Inventors

• Tschritter Jonathan Samuel

Classifications

• G01N33/44

  Resins; Plastics; Rubber; Leather · CPC title

• D01F6/605

  from aromatic polyamides · CPC title

• C01B17/96

  Methods for the preparation of sulfates in general (particular individual sulfates, see the relevant groups of subclasses C01B - C01G, according to the cation) · CPC title

• G01J3/30

  Measuring the intensity of spectral lines directly on the spectrum itself (G01J3/42, G01J3/44 take precedence) · CPC title

• G01N31/12 Primary

  using combustion (G01N25/20 takes precedence) · CPC title