Sample preparation for gas analysis using inductive heating
Improved gas analysis for non-gaseous samples is provided by placing the sample in direct contact with an inductive heating element, followed by inductively heating the heating element to provide gas for analysis. Disposable sample vials including such a heating element can be employed, or a sample tube including an inductive heating element can be configured to mate to the input gas line of a gas analysis system.
1 . An analysis method for non-gaseous samples, the method comprising:
providing a sample vial including a heating element capable of being inductively heated;
placing a non-gaseous sample in the sample vial in contact with the heating element;
sealing the vial;
inductively heating the heating element to liberate one or more gaseous analytes from the sample; and
performing gas analysis of the gaseous analytes.
2 . The method of claim 1 , wherein sealing the vial entails providing a mechanical force tending to crush the non-gaseous sample.
3 . The method of claim 1 , wherein the gaseous analytes comprise one or more analytes selected from the group consisting of: H 2 O, CO 2 , NH 3 , H 2 S, H 2 CO, C 2 H 4 , and CO.
4 . The method of claim 1 , wherein the gaseous analytes are provided by direct volatilization of one or more compounds present in the sample.
5 . The method of claim 1 , wherein the gaseous analytes are provided as one or more products of one or more chemical reactions having one or more compounds present in the sample as one or more reactants.
6 . The method of claim 1 , wherein the non gaseous sample comprises one or more samples selected from the group consisting of: bound liquids in a solid matrix, plant material, animal tissue, soil samples, food products, suspensions, ointments, creams, industrial products, pharmaceutical products, and industrial products.
7 . The method of claim 1 , further comprising passing the gaseous analytes through a filter element.
8 . The method of claim 7 , wherein the filter element comprises a sorbent that preferentially removes interfering compounds.
9 . The method of claim 7 , wherein the filter element comprises a heater and sacrificial surface to remove organic compounds.
10 . The method of claim 1 , further comprising concentrating the gaseous analytes in a cold trap prior to the gas analysis.
11 . The method of claim 1 , further comprising diluting the gaseous analytes with one or more inert gases prior to the gas analysis.
12 . The method of claim 1 , further comprising passing the gaseous analytes through a chromatography separation column.
13 . The method of claim 1 , wherein the gas analysis comprises one or more optical analysis techniques based on optical spectroscopy.
14 . The method of claim 1 , wherein the optical analysis techniques include one or more techniques selected from the group consisting of: cavity ring-down spectroscopy, intracavity absorption spectroscopy, and cavity-enhanced absorption spectroscopy.
15 . The method of claim 1 , wherein the inductively heating and performing gas analysis are performed at two or more distinct sample temperatures.
16 . The method of claim 1 , further comprising replacing the heating element with an unused heating element after analysis of a single sample.
17 . The method of claim 1 , wherein the sealing the vial is performed under controlled gaseous ambient conditions.
18 . The method of claim 1 , wherein the sealing the vial is performed under uncontrolled gaseous ambient conditions.
19 . Apparatus for analysis of non-gaseous samples, the apparatus comprising:
a sample vial including a heating element capable of being inductively heated;
wherein the vial is configured such that a non-gaseous sample placed in the vial is in direct contact with the heating element; and
wherein the vial is configured such that it can be sealed.
20 . The apparatus of claim 19 , wherein the vial is configured to apply a mechanical force tending to crush the non-gaseous sample when the vial is sealed.
21 . The apparatus of claim 19 , wherein the heating element has a magnetic permeability of 10 mH/m or more.
22 . The apparatus of claim 19 , wherein the apparatus is configured to accept a sample selected from the group consisting of: bound liquids in a solid matrix, plant material, animal tissue, soil samples, food products, suspensions, ointments, creams, industrial products, pharmaceutical products, and industrial products.
23 . The apparatus of claim 19 , wherein the heating element is disposable.
24 . The apparatus of claim 23 , wherein the vial and heating element are both disposable.
25 . The apparatus of claim 19 , wherein the heating element is configured as a sample holder.
26 . The apparatus of claim 25 , wherein the heating element is configured as a deformable sheet or foil that can be crimped around the sample.
27 . The apparatus of claim 19 , wherein the vial is configured such that it can be sealed under controlled gaseous ambient conditions.
28 . The apparatus of claim 19 , wherein the vial is configured such that it can be sealed under uncontrolled gaseous ambient conditions.
29 . Apparatus for analysis of non-gaseous samples, the apparatus comprising:
an analytical instrument having an input gas line; and
a sample tube including a heating element capable of being inductively heated, wherein the sample tube is configured to be capable of mating to the input gas line;
wherein the sample tube is configured such that a non-gaseous sample placed in the sample tube is in direct contact with the heating element.