Determination of metal and metalloid concentrations using ICPMS

Patent metadata

Field	Value
Publication number	US-9406490-B1
Application number	US-201514703828-A
Country	US
Kind code	B1
Filing date	May 4, 2015
Priority date	May 2, 2014
Publication date	Aug 2, 2016
Grant date	Aug 2, 2016

Abstract

A system for determining an analyte by inductively coupled plasma mass spectrometry (ICPMS) includes a sample introduction device having a heated cyclonic spray chamber. The system is configured to introduce sample that includes a metal and/or a metalloid having an organic interferent. The system also includes an inductively coupled plasma mass spectrometry device with a collision/reaction cell configured to receive a mixture of gases including both ammonia and hydrogen. A method includes introducing a sample to plasma to produce a characteristic spectrum associated with an elemental composition of the sample. The method also includes introducing both ammonia and hydrogen to a collision/reaction cell to remove carbon-based interferences to detection of the sample prior to determining the elemental composition of the sample.

First claim

What is claimed is:

1. A method for determining an analyte by inductively coupled plasma mass spectrometry (ICPMS), the method comprising:
introducing a sample to a plasma to produce a characteristic spectrum associated with an elemental composition of the sample, the sample including at least one of a metal or a metalloid having an organic interferent; and
prior to determining the elemental composition of the sample, introducing both ammonia and hydrogen to a collision/reaction cell to remove at least one carbon-based interference to detection of the analyte.

2. The method as recited in claim 1 , wherein the analyte comprises silicon.

3. The method as recited in claim 1 , wherein the organic interferent is related to the presence of organic matter in the sample.

4. The method as recited in claim 1 , wherein the sample is introduced at a sample flow rate between one microliter per minute (1 μL/min) and fifty microliters per minute (50 μL/min).

5. The method as recited in claim 1 , wherein the ammonia is added at a flow rate between one-tenth of a milliliter per minute (0.1 mL/min) and one milliliter per minute (1 mL/min).

6. The method as recited in claim 1 , wherein the hydrogen is added at a flow rate between one-half of a milliliter per minute (0.5 mL/min) and five milliliters per minute (5 mL/min).

7. The method as recited in claim 1 , further comprising preparing the sample for analysis in a heated cyclonic spray chamber prior to introducing the sample to the plasma.

8. The method as recited in claim 7 , wherein the heated cyclonic spray chamber is heated to a temperature sufficient to volatilize the organic interferent.

9. A system for determining an analyte by inductively coupled plasma mass spectrometry (ICPMS), the system comprising:
a sample introduction device having a heated cyclonic spray chamber and configured to introduce a sample at a sample flow between one microliter per minute (1 μL/min) and fifty microliters per minute (50 μL/min), the sample including at least one of a metal or a metalloid having an organic interferent; and
an inductively coupled plasma mass spectrometry device including a collision/reaction cell configured to receive a mixture of gases including both ammonia and hydrogen.

10. The system as recited in claim 9 , wherein the analyte comprises silicon.

11. The system as recited in claim 9 , wherein the organic interferent is related to the presence of organic matter in the sample.

12. The system as recited in claim 9 , wherein the system is configured to add the ammonia at a flow rate between one-tenth of a milliliter per minute (0.1 mL/min) and one milliliter per minute (1 mL/min).

13. The system as recited in claim 9 , wherein the system is configured to add the hydrogen at a flow rate between one-half of a milliliter per minute (0.5 mL/min) and five milliliters per minute (5 mL/min).

14. The system as recited in claim 9 , wherein the heated cyclonic spray chamber is configured to be heated to a temperature sufficient to volatilize the organic interferent.

15. A method for determining an analyte by inductively coupled plasma mass spectrometry (ICPMS), the method comprising:
introducing a sample to a plasma to produce a characteristic spectrum associated with an elemental composition of the sample, the sample including silicon having an organic interferent; and
prior to determining the elemental composition of the sample, introducing both ammonia and hydrogen to a collision/reaction cell to remove at least one carbon-based interference to detection of the silicon.

16. The method as recited in claim 15 , wherein the organic interferent is related to the presence of organic matter in the sample.

17. The method as recited in claim 15 , wherein the ammonia is added at a flow rate between one-tenth of a milliliter per minute (0.1 mL/min) and one milliliter per minute (1 mL/min).

18. The method as recited in claim 15 , wherein the hydrogen is added at a flow rate between one-half of a milliliter per minute (0.5 mL/min) and five milliliters per minute (5 mL/min).

19. The method as recited in claim 15 , wherein the sample is prepared for analysis in a heated cyclonic spray chamber.

20. The method as recited in claim 19 , wherein the heated cyclonic spray chamber is heated to a temperature sufficient to volatilize the organic interferent.

Assignees

• Elemental Scientific Inc

Inventors

• Saetveit Nathan
• Wiederin Daniel R

Classifications

• H01J49/105 Primary

  using high-frequency excitation, e.g. microwave excitation, Inductively Coupled Plasma [ICP] · CPC title

• H01J49/145

  using chemical ionisation · CPC title

• H01J49/0031

  Step by step routines describing the use of the apparatus (H01J49/0081 takes precedence) · CPC title

• H01J49/045

  with means for using a nebulising gas, i.e. pneumatically assisted · CPC title

• H01J49/0077

  specific reactions other than fragmentation · CPC title