Method for analysis of perchlorate

• US 20060144786A1
• Filed: 03/03/2006
• Published: 07/06/2006
• Est. Priority Date: 06/23/2004
• Status: Active Grant

• Current Assignee: Kham Lin
• Original Assignee: Kham Lin
• Inventors: Lin, Kham
• Granted Patent: US 7,393,453 B2
• Time in Patent Office: Days
• US Class Current: 210/635
• CPC Class Codes: B01D 15/325 Reversed phase
• CPC Class Codes: B01D 15/34 Size selective separation, e.g. size exclusion chromatography, gel filtration, permeation
• CPC Class Codes: B01D 15/426 Specific type of solvent
• CPC Class Codes: G01N 30/02 Column chromatography
• CPC Class Codes: G01N 30/7233 interfaced to liquid or supercritical fluid chromatograph interfaces in general for introducing or extracting samples to be analysed with specially adapted mass spectrometer, see H01J49/04
• CPC Class Codes: G01N 33/182 specific anions in water electrochemical analysis G01N27/26; detection of ions by colorimetry G01N31/22
• CPC Class Codes: Y10T 436/19 Halogen containing
• CPC Class Codes: Y10T 436/193333 In aqueous solution

Abstract

A method for analyzing the content of perchlorate in a sample matrix comprising the steps of extracting the sample matrix and applying it to a reverse phase column, followed by elution with a mobile phase. The reverse phase column optionally has a protein coating deposited thereon.

Claims

1. A method for the quantification of perchlorate in a sample comprising the steps of;

v. providing an extract of a sample, said extract containing the

perchlorate to be quantified,

vi. applying the extract to a stationary phase support,

vii. eluting the extract with a mobile phase comprising an organic

solvent, water and organic acid, and

viii. detecting the eluted perchlorate.

2. The method of claim 1, in which the stationary reverse phase support comprises an alkylated base material, said base material being selected from the group consisting of silica, alumina, zirconia, polystyrene, polyacrylamide, and styrene-divinyl copolymers.

3. The method of claim 2 in which the stationary support further comprises a protein coating.

4. The method of claim 1, in which the organic solvent is selected from the group consisting of methanol, ethanol, acetonitrile, ethyl acetate, and 2-propanol.

5. The method of claim 1 in which the mobile phase has a composition of between 5% and 95% by volume of organic solvent, 5% and 95% by volumne of water and 0.05% and 5% by volume of organic acid.

6. The method of claim 2, in which the surface of said alkylated base material is alkylated with hydrocarbon chains containing from 4-18 carbon atoms.

7. The method of claim 1, in which the perchlorate is detected by mass spectrometry.

8. The method of claim 7, in which the perchlorate is detected at a mass of 83 and 85.

9. The method of claim 1 further comprising the step of adding an internal standard to the extract.

10. The method of claim 9 in which the internal standard comprises perchlorate in which O16 is partially replaced by heavy Oxygen (O18).

11. The method of claim 9, where said internal standard is detected at a mass of 89 or 91 or both 89 and 91 together.

12. The method of claim 10, where isotopic mass ratios of chlorine 35 to chlorine 37 in the perchlorate standard comprising O18 are used for confirmation.