A thermal conductivity detector includes a first pipe path that houses a filament, a second pipe path and a third pipe path that connects the first pipe path to the second pipe path. In the third pipe path, first, second and third gas lead-in portions are arranged in this order from the first pipe path toward the second pipe path. A carrier gas is led to the first and third gas lead-in portions alternately, and a sample gas is led to the second gas lead-in portion. The distance between the second and third gas lead-in portions is equal to or smaller than 1.3 times of a maximum dimension of an opening formed at the second gas lead-in portion. At least part of the third pipe path between the second gas lead-in portion and the third gas lead-in portion has a cross sectional area that is equal to or smaller than an area of the opening formed at the second gas lead-in portion.

The disclosed system and method improve analysis of chemical samples for measurement of trace volatile chemicals, such as by Gas Chromatography (GC) and Gas Chromatography/Mass Spectrometry (GCMS). The system can include two traps in series, the first of which removes most of the unwanted water vapor, while the second trap preconcentrates the sample using a series of capillary columns of increasing adsorption strength. The sample can be backflushed from the second trap directly to a chemical analyzer without splitting which can maximize sensitivity. The system improves elimination of water vapor and fixed gases from the sample prior to analysis, resulting in detection limits as low as 0.001 PPBb. The second trap allows faster release of the sample upon injection to the chemical analyzer without additional focusing, and can be cleaned up faster when exposed to high concentration samples relative to packed traps.

The present invention relates to a method for detecting and/or quantifying an analyte in a sample using mass spectrometry. The method of the invention comprises: extracting the analyte from the sample using solid phase extraction (SPE) so as to obtain an SPE extract comprising the analyte, concentrating the analyte, said concentrating comprising evaporating solvent from the SPE-extract; and detecting and/or quantifying the analyte in the sample using mass spectrometry.

The present invention relates to a method for detecting and/or quantifying an analyte in a sample using mass spectrometry. The method of the invention comprises: extracting the analyte from the sample using solid phase extraction (SPE) so as to obtain an SPE extract comprising the analyte, concentrating the analyte, said concentrating comprising evaporating solvent from the SPE-extract; and detecting and/or quantifying the analyte in the sample using mass spectrometry.

A method of determining total organofluorine in a sample comprising PFAS, comprising: providing a solution of PFAS in an organic solvent to obtain extracted PFAS, or extracting a sample with an organic solvent to obtain extracted PFAS; treating the extracted PFAS with a sodium metal dispersion and alcohol to obtain sodium fluoride; and quantifying the amount of the fluoride. Surprisingly, we discovered that the method recovered substantial fluorine from PFAS and significantly higher yields obtained by selection of the appropriate alcohols. The method is selective for organofluorine from inorganic fluorine.

A method of determining total organofluorine in a sample comprising PFAS, comprising: providing a solution of PFAS in an organic solvent to obtain extracted PFAS, or extracting a sample with an organic solvent to obtain extracted PFAS; treating the extracted PFAS with a sodium metal dispersion and alcohol to obtain sodium fluoride; and quantifying the amount of the fluoride. Surprisingly, we discovered that the method recovered substantial fluorine from PFAS and significantly higher yields obtained by selection of the appropriate alcohols. The method is selective for organofluorine from inorganic fluorine.

Technologies for rapid equilibration for water isotope analysis are disclosed. In at least one illustrative embodiment, a vaporizer may include an injection block that defines a chamber and a septum positioned over an inlet of the chamber to seal the chamber. The chamber may be configured to be fluidly coupled to a pump to develop a vacuum within the chamber, and the septum may be configured to receive a needle that is inserted into the chamber. A thermally conductive wool may be positioned within the chamber and may be configured to receive a tip of the needle.

Technologies for rapid equilibration for water isotope analysis are disclosed. In at least one illustrative embodiment, a vaporizer may include an injection block that defines a chamber and a septum positioned over an inlet of the chamber to seal the chamber. The chamber may be configured to be fluidly coupled to a pump to develop a vacuum within the chamber, and the septum may be configured to receive a needle that is inserted into the chamber. A thermally conductive wool may be positioned within the chamber and may be configured to receive a tip of the needle.

An improved liquid vaporization and conditioning system, and associated method, for efficiently vaporizing a liquid sample for accurately determining the constituent components thereof providing enhanced flow rate, pressure and thermal control, the improvement including a combination of a resistance temperature detector, a sweeping bend to, an in-line thermal break, a flow buffering input manifold, enhanced multi-path heater vaporizer construction with four heater units, a vaporizer output mixing manifold and control elements providing a capability for partial shutdown in the event of compromised heating or flow anomalies without risk of flow loss/volume capacity beyond a permissible threshold and an improved, modular heat vaporizer enclosure.

A method for simultaneous determination of nitrogen and oxygen isotope compositions of natural nitrate and nitrite, which quantitatively converts natural nitrate and nitrite into an organic ester and a nitro-compounds respectively, and then nitrate and nitrite δ.sup.18O and δ.sup.15N are simultaneously determined by adopting a gas chromatography/pyrolysis/gas chromatography/isotope ratio mass spectrometry coupling technology (GC/Py/GC/IRMS). According to the method for simultaneously determining the nitrogen and oxygen isotope compositions of the natural nitrate salt and nitrite salt, the small amount of sample does not result in the loss, acquisition, exchange and fractionation of nitrogen and oxygen.