Abstract: Disclosed is a micro gas chromatography system including a fluid feeder for feeding a fluid composed of a carrier gas and a gas mixture containing an analyte component to the next stage, a micro gas preconcentrator chip configured to concentrate and desorb the analyte component contained in the fluid, a micro gas chromatography chip including a micro separation column for separating the analyte component concentrated and desorbed by the micro gas preconcentrator chip, and a micro sensing unit including a micro thermal conductivity detection sensor configured to detect the analyte component separated by the micro gas chromatography chip.

Abstract: Disclosed is a dispersion plate for a purification column including a support plate, at least one first fluid tube penetrating through the support plate, and a plurality of second fluid tubes arranged to be spaced apart from the first fluid tube and surround the first fluid tube, wherein a length of at least one of the second fluid tubes is longer than lengths of another second fluid tubes, and is shorter than or equal to a length of the first fluid tube.

Abstract: A drying device comprising a regenerable desiccant medium that is effective to adsorb water without absorption of gaseous analyte species in an introduced ambient air stream is described. The drying device can be used with a thermal desorption device to remove water vapor from gaseous analyte species prior to analysis of the gaseous analyte species. Systems including a drying device are also described.

Abstract: The present invention relates to an optical emission spectrometer with at least one spark chamber. It comprises an oblong electrode being arranged inside thereof and at least one inlet for an inert gas. Here, the inert gas inlet is arranged such that the inert gas flows around the electrode along its longitudinal axis. In the sense of the invention, in the inert gas entry and/or between inert gas entry and electrode at least one sieve-like insert is provided and/or the electrode in the flow cross-section of the inter gas flow is surrounded by at least one sieve-like insert.

Abstract: A portable gas analysis apparatus for conducting a gas flow, in particular for highly volatile compounds, includes a seeker measurement path and a separation measurement path. The seeker measurement path extends from a sample gas inlet opening to a first air exit opening, wherein a connecting path branches off from the seeker measurement path to a separation measurement path, and said separation measurement path extends from the connecting path to a second air exit opening and is connected to a carrier gas inlet opening, wherein the gas analysis apparatus has a control element which is designed for reversing the gas flow in the connecting path.

Abstract: Aspects of enhanced nanoscale gas chromatography are described. In one embodiment, a nano-scale gas chromatography (GC) module includes a light source, a light detector, and a sensor module having vertically-integrated photonic crystal slab (PCS) Fano resonance filter and GC channel layers. The PCS Fano resonance filter layer includes a hole lattice region, and the GC channel layer comprises a gas channel for separation of analytes in a gas mixture. The gas channel includes a coiled section and an extended length section, where the extended length section extends through a region in the GC channel layer that is stacked in proximity with the hole lattice region. The hole lattice region in the PCS Fano resonance filter layer provides local field enhancement of light generated by the light source for increased light-matter interaction with the analytes in the gas channel.

Abstract: A non-methane total hydrocarbons analysis apparatus and method are introduced. The analysis apparatus includes a six-pass valve, quantification ring, first stored gas pipe, second stored gas pipe, multi-pass valve, molecular sieve filling pipe, first air source, and detector. The six-pass valve and the multi-pass valve are configured to have a load status bit. A gas under test passes through the molecular sieve to remove non-methane total hydrocarbons such that the treated gas functions as a background gas for filling the first stored gas pipe and the second stored gas pipe. The six-pass valve and the multi-pass valve are configured to have an entered sample status bit such that zero-grade compressed air drives the gas inside the second stored gas pipe, quantification ring, and first stored gas pipe to enter the detector. The background gas inside the second stored gas pipe and the second stored gas pipe provides a baseline.

Abstract: An HPLC apparatus includes a heat exchanger formed from diffusion-bonded first and second titanium substrates. At least two conduits for counterflow are defined between the first and second substrates.

Abstract: A gas chromatography equipment includes a sample introducer, a detector, a column module, and an oven including a housing. A sub-space is provided in a projection section projecting downward from a portion of a bottom face of the housing communicates with a main space of the housing. A column module attaching section is provided outside the housing and below the main space. A fixed side face, which faces the column module attaching section, of the projection section serves as an attachment face for attaching the column module. The column module is attached to the housing in such a way that the main flat surface of the column module is horizontally positioned with an end face of the column module being the attachment face.

Abstract: Provided is a plate-type column which allows the temperature of its inner passage to be rapidly increased or decreased while ensuring the correctness of an analysis or other operations. A plate-type column 10 includes: a plate-shaped main body 11; projecting portions 12 and 13 protruding from a circumferential edge of the main body 11; and a fluid-flow passage 14 extending in the main body 11 and the projecting portions 12 and 13. An intermediate portion of the passage 14 is provided in the main body 11, while each of the end portions of the passage 14 extends from the main body 11 through the projecting portion 12 or 13, with each of the end portions being open to the outside at the tip of the projecting portion 12 or 13.

Abstract: An article of laboratory glassware for directing the flow of chemical materials is described. The article includes a glass manifold having a plurality of input ports and at least one output port, and a plurality of stopcocks. Each stopcock has an inlet port and an outlet port connected by a passageway through the plug. Each of the stopcock output ports is connected to one of the manifold input ports, and each of the stopcock input ports is connected with one end of a hollow glass tube, and the other end of the hollow glass tube is connected to a ground glass joint. The output ports of the manifold are terminated to a ground glass joint. Each plug is rotated by a stepper motor or D.C. electrical motor, and sensed by a sensor. The rotation of each rotating plug is controlled by a computer.

Abstract: In accordance with one embodiment of the present disclosure, a method for processing a liquid test sample includes using a needle assembly to introduce a first flow of gas through an inlet in the needle assembly into a container containing a liquid test sample and to provide an outlet from the container through the needle assembly, separating at least one volatile component from the sample in a gas and liquid separator using the first flow of gas, adsorbing the at least one volatile component onto a trapping material to provide at least one adsorbed component, and releasing the at least one adsorbed component from the trapping material to provide at least one released component.

Abstract: Novel porous materials comprising nanoparticles, use in chromatographic separations, processes for its preparation, and separations devices containing the chromatographic material are described by the instant invention. In particular, the disclosure describes porous inorganic/organic hybrid particles embedded with nanoparticles selected from oxides or nitrides of the following: silicon carbide, aluminum, diamond, cerium, carbon black, carbon nanotubes, zirconium, barium, cerium, cobalt, copper, europium, gadolinium, iron, nickel, samarium, silicon, silver, titanium, zinc, boron, and mixtures thereof.

Abstract: A housing of a column unit is tubular-shaped, and includes a first opening and a second opening, and an inner space separated from outside air by an insulating material. An air cooling section including a cooling device is arranged on a side of the first opening of the housing. At the time of cooling the inside of the inner space of the housing, air is caused, by a fan, to flow through the air cooling section and from the side of the first opening to a side of the second opening. A column section including a separation column and a heater is arranged inside the housing. A gap through which air flows from the first opening to the second opening is formed between the column section and an inner wall of the inner space of the housing.

Abstract: The present invention provides a new design for high capacity stationary phases for chromatography, for example, ion chromatography. The stationary phases include a first polymer layer in contact with and at least partially coating the substrate of the stationary phase. The first polymer layer serves as a foundation for the attachment, and in various embodiments, the growth and attachment, of a highly hyperbranched polymer structure, typically based on one or more products of condensation polymerization. Multiple components are of use in forming the first polymer layer and the hyperbranched polymer structure, thereby providing a stationary phase that can be engineered to have a desired property such as ion capacity, ion selectivity, and the like. Exemplary condensation polymers are formed by the reaction of at least one polyfunctional compound with at least one compound of complimentary reactivity, e.g., a nucleophilic polyfunctional compound reacting with an electrophilic compound.

Abstract: An efficient absorption spectroscopy system is provided. The spectroscopy system may be configured to measure solid, liquid or gaseous samples. Vacuum ultra-violet wavelengths may be utilized. Some of the disclosed techniques can be used for detecting the presence of trace concentrations of gaseous species. A preferable gas flow cell is disclosed. Some of the disclosed techniques may be used with a gas chromatography system so as to detect and identify species eluted from the column. Some of the disclosed techniques may be used in conjunction with an electrospray interface and a liquid chromatography system so as to detect and identify gas phase ions of macromolecules produced from solution. Some of the disclosed techniques may be used to characterize chemical reactions. Some of the disclosed techniques may be used in conjunction with an ultra short-path length sample cell to measure liquids.

Abstract: A method for semi-automatically generating configuration information for a gas chromatograph uses an identification device reader of the gas chromatograph to 1) determine a presence and location of sample flow component identification devices in or on identification device holders that hold the sample flow component identification devices; 2) read information from sample flow component identification devices held in the identification device holders; and 3) output configuration information for the gas chromatograph. The configuration information is based on the presence and location of particular sample flow component identification devices in or on particular identification device holders, and on associations of particular identification device holders with particular sample flow component connections to the gas chromatograph. The configuration information indicates if and how sample flow components are connected to the gas chromatograph.

Abstract: A system for analyzing a gas mixture, including at least one chromatography column, a mechanism injecting the mixture into the column, and a mechanism detecting compound(s) forming the gas mixture, the detection mechanism including at least one detector of nanosensor type of an outlet of the column and a detector of nanosensor type in the column, capable of detecting passage of the compounds. It is then possible to determine the velocity of each of the compounds within the system.

Abstract: In some embodiments, apparatus and systems, as well as methods, may operate to draw a formation fluid sample into a sampling port included in a down hole tool, to vaporize some part of the fluid sample to substantially fill an injection port with a gas phase, to differentiate gas components in the gas phase to provide differentiated gas components along a concentration gradient, to detect the differentiated gas components, and to determine a fingerprint of the differentiated gas components. Other apparatus, systems, and methods are disclosed.

Abstract: Disclosed herein are two stage thermal modulators that are useful in the separation of the components of an analyte sample in an analytical method, such as gas chromatography. In some embodiments, the thermal modulators described herein include a modulator column coupled to at least one ground point so as to define a plurality of stages that may be independently temperature modulated. In some cases, the modulator column (or stages thereof adjacent to a ground point) and the ground point are thermally matched, so as to limit or eliminate the formation of a temperature differential between the modulator column and a ground point.

Abstract: A non-seizing taper used for purged capillary tubing connections in gas chromatography that stops capillary tubing at a predictable position within the taper during installation and maintains space for gas to flow past the capillary tubing. The disclosed taper is an improved component of commonly used purged devices such as inlet liners and purged unions. The arresting aspect of the taper simplifies the process of capillary tubing installation while ensuring that the tubing will reproducibly be positioned in the taper. One or more features of the taper prevent tubing from seizing within the taper so that the devices can be reused and ensure that there is open space for a portion of gas to flow around and past the tubing. The angle of the taper, the dimensions of the taper, and the nature of the features within the taper can be adjusted to meet specific performance, usability and/or manufacturability requirements.

Abstract: A gas chromatography (GC) system comprises: a sample injector adapted to receive a liquid sample into an interior cavity thereof and to volatilize the liquid sample; a GC column configured to receive the volatilized sample from the sample injector; a carrier gas inlet line fluidically coupled to a gas inlet port of the sample injector; a septum purge vent line fluidically coupled to a first gas outlet port of the sample injector; a split-flow vent line fluidically coupled to a second gas outlet port of the sample injector; and a vacuum system configured to apply vacuum to the septum purge vent line, the split-flow vent line and the interior cavity of the sample injector. Alternatively, the vacuum system may be coupled to a vacuum port of the sample injector. A separate flow of helium gas may be supplied to an inlet of the GC column.

Abstract: A system for analyzing a gas mixture, including at least one chromatography column, a mechanism injecting the mixture into the column, and a mechanism detecting compound(s) forming the gas mixture, the detection mechanism including at least one detector of nanosensor type of an outlet of the column and a detector of nanosensor type in the column, capable of detecting passage of the compounds. It is then possible to determine the velocity of each of the compounds within the system.

Abstract: A non-seizing taper used for purged capillary tubing connections in gas chromatography that stops capillary tubing at a predictable position within the taper during installation and maintains space for gas to flow past the capillary tubing. The disclosed taper is an improved component of commonly used purged devices such as inlet liners and purged unions. The arresting aspect of the taper simplifies the process of capillary tubing installation while ensuring that the tubing will reproducibly be positioned in the taper. One or more features of the taper prevent tubing from seizing within the taper so that the devices can be reused and ensure that there is open space for a portion of gas to flow around and past the tubing. The angle of the taper, the dimensions of the taper, and the nature of the features within the taper can be adjusted to meet specific performance, usability and/or manufacturability requirements.

Abstract: Methods and related systems are described for improving component separations in chromatography through novel techniques. The improvements in separation is due primarily to the provision of differential acceleration of the components being separated. Various systems and methods for providing differential acceleration are described including: increasing the cross section of the column towards the column outlet, changing the thickness or other composition of stationary phase within the column, and providing a temperature and/or mobile phase velocity gradient along the column.

Abstract: A gas adsorbing column filled with a filler composed of an adsorbent supported on a substrate having an average particle size or cross-sectional average diameter of 500 ?m to 1000 ?m, wherein the void volume of the column is 5 to 100 ?l.

Abstract: An inlet liner is provided for use in an inlet assembly of a chromatograph system. The inlet liner has an elongate tube that extends along a longitudinal axis and defines a bore that extends along the longitudinal axis and has an inner bore surface. At least one projection extends from the inner bore surface into the bore. Chromatograph systems are provided including the exemplary inlet liner(s). Methods are also provided for analyzing a sample containing a matrix in a chromatograph system having an inlet assembly connected to a chromatograph column. The method includes positioning an exemplary inlet liner in the inlet assembly, flowing the sample through the inlet liner, and adhering a portion of the matrix to a projection surface of at least one projection of the inlet liner.

Abstract: A modulator for simply providing fast and precise sampling of a chromatographic peak eluting from a first column into a second column of a comprehensive two-dimensional gas chromatograph, where the modulator includes a planar component containing a first gas passage for connecting a carrier gas source to the second separation column, a second gas passage for connecting the first separation column to an exhaust outlet, a connecting gas passage between the first and second gas passages, and two individually controllable open/close valves arranged in parallel connection in the first gas passage between its connection to the carrier gas source and the branch-off of the connecting gas passage, and where the gas passages and valves are formed in the planar component by micromachining.

Abstract: A fast gas chromatograph (GC) method and device for obtaining fast gas chromatography analysis, in which a capillary gas chromatography column is inserted into a resistively heated metal tube located mostly outside a heated oven, which serves as a heated transferline to a flexible column that enters a resistively heated metal tube from a gas chromatograph injector and exits into a gas chromatograph detector. The resistively heated metal tube of the fast GC device has an internal diameter that is over twice the external diameter of the GC column so as to enable the insertion of several capillary GC column loops. The process of column insertion into or removal from the heated tube is aided by touching it with an ultrasound vibrating device that remarkably reduces the friction during column insertion into the metal tube heater.

Abstract: Device for analysis by gas phase chromatography comprising: a chromatography micro-column, a detection module comprising at least one NEMS and/or MEMS type detector arranged in channel, a direct fluidic connection between an evacuation end of the chromatography micro-column and an admission end of the channel of the detection module, a thermoelectric module, the hot face heating the chromatography micro-column and the cold face cooling the detection module.

Abstract: Embodiments of the present invention provide columns for use in gas chromatography and methods of making and using such columns. The present invention provides a folded passage column: a fluid passage formed by joining a first channel in a first surface through a slot to a second channel in a second surface. In some embodiments, a folded passage column repeats that building block, joining a plurality of channels in a first surface with a plurality of channels in a second surface such that the channels link to form a continuous passage.

Abstract: The present disclosure relates to a spirally wrapped chromatographic structure, a system incorporating such structure and a method of providing such structure. The structure may include an absorber layer having a first surface and a second surface, wherein one or a plurality of channels are defined in the first surface. The structure may also include a support layer having a first surface and a second surface, the first surface of the support layer disposed on the second surface of the absorber layer, wherein the absorber layer and the support layer comprise a spiral configuration such that at least a portion of the first surface of the absorber layer contacts at least a portion of the second surface of the support layer.

Abstract: Ionic liquid (IL)-mediated sol-gel hybrid organic-inorganic materials present enormous potential for effective use in analytical microextraction. One obstacle to materializing this prospect arises from high viscosity of ILs significantly slowing down sol-gel reactions. A method was developed which provides phosphonium-based, pyridinium-based, and imidazolium-based IL-mediated advanced sol-gel organic-inorganic hybrid materials for capillary microextraction. Scanning electron microscopy results demonstrate that ILs can serve as porogenic agents in sol-gel reactions. IL-mediated sol-gel coatings prepared with silanol-terminated polymers provided up to 28 times higher extractions compared to analogous sol-gel coatings prepared without any IL in the sol solution.

Abstract: Provided is a plate-type column which allows the temperature of its inner passage to be rapidly increased or decreased while ensuring the correctness of an analysis or other operations. A plate-type column 10 includes: a plate-shaped main body 11; projecting portions 12 and 13 protruding from a circumferential edge of the main body 11; and a fluid-flow passage 14 extending in the main body 11 and the projecting portions 12 and 13. An intermediate portion of the passage 14 is provided in the main body 11, while each of the end portions of the passage 14 extends from the main body 11 through the projecting portion 12 or 13, with each of the end portions being open to the outside at the tip of the projecting portion 12 or 13.

Abstract: In a fast gas chromatograph (GC) method and device for obtaining fast gas chromatography analysis, a capillary gas chromatography column is inserted into a resistively heated metal tube located mostly outside a standard gas chromatograph oven, which may serve as a heated transfer line to a flexible column that enters the resistively heated metal tube from its injector and exits into its detector. The fast GC device enables less than one minute full range temperature programming and cooling back analysis cycle time. The fast GC according to one embodiment is combined with mass spectrometry with supersonic molecular beams for the provision of fast analysis cycle time together with highly informative mass spectral information for improved sample analysis and identification.

Abstract: A flow through cartridge for solid phase extraction of an analyte from a liquid has a cartridge body bounding a passage for retaining a sorbent. The passage extends from a first end face to a second end face, opposite the first end face of the cartridge body. The cartridge body is composed of a core of a first material extending around the passage and sealing rings of a second material, extending around an axis of the passage at the first and second end faces. Surface portions of the sealing rings constituting surface portions of the first and second end faces. The first material is stronger and stiffer than the second material.

Abstract: Certain aspects and examples are directed to sorbent devices and methods of using them. In certain embodiments, a sorbent device comprising a body comprising a sampling inlet, a base and a longitudinal diffusion path between the inlet and the base is provided. In some embodiments, the sorbent device can include at least two sorbent materials fluidically coupled to the longitudinal diffusion path, in which the sorbent materials are arranged from a material with a weakest sorbent strength to a material with a strongest sorbent strength with the weakest sorbent strength material adjacent to the sampling inlet.

Abstract: A method for the in-instrument recombination of volatiles using a gas chromatograph with mass spectrometry and olfactometry detection is described. Compounds that are introduced into the modified GC are separated conventionally on an analytical capillary GC column. The elution profile of volatiles can be segmented, analyzed and arbitrarily combined. In-line with the GC column, a pneumatic flow switch and splitter are connected to a detector and olfactometer. A cold trap allows the user to build a mixture of separated volatiles that is held until the cryotrap is rapidly heated, releasing the mixture for a subject to smell at the olfactory port and to evaluate. The instrument allows for characterization of the aroma quality of specific fractions of aroma volatiles obtained from foods, flowers or beverages without the need for pure chemical standards or the calculation of individual compound concentrations or sensory thresholds.

Abstract: Methods and related systems are described for improving component separations in chromatography through novel techniques. The improvements in separation is due primarily to the provision of differential acceleration of the components being separated. Various systems and methods for providing differential acceleration are described including: increasing the cross section of the column towards the column outlet, changing the thickness or other composition of stationary phase within the column, and providing a temperature and/or mobile phase velocity gradient along the column.

Abstract: A gas chromatographic device comprises an inlet system and a chromatography column. The inlet system includes a liner having pressure reducing means contained therein for reducing pressure between an inlet of the pressure reducing means and an outlet of the pressure reducing means. When the devise is in use, the chromatography column is positioned in the liner of the inlet system downstream from the pressure reducing means, and the chromatography column is under vacuum at its outlet.

Abstract: A column used for gas chromatography (GC) is fabricated from an open tubular light guiding capillary. The light guiding capillary is suitable for transmission of optical frequencies employed in commercially available hand held laser range finders.

Abstract: The present invention provides a gas chromatography—inverse gas chromatography combined analysis device, which includes a gas chromatography column and an inverse gas chromatography column, an input end of the gas chromatography column is connected to a sample feeder, an output end of the gas chromatography column is connected to an input end of the inverse gas chromatography column, the output end of the gas chromatography column is further connected to a first detector, the input end of the inverse gas chromatography column is further connected to a carrier gas tube, an output end of the inverse gas chromatography column is connected to a second detector, and the first detector and the second detector are both connected to a signal collector.

Abstract: Apparatus and systems, as well as methods, may operate to draw a formation fluid sample into a sampling port included in a down hole tool or tool body, to vaporize some part of the fluid sample to substantially fill an injection port with a gas phase, to differentiate gas components in the gas phase to provide differentiated gas components along a concentration gradient in a receiving section, to detect the differentiated gas components with a detector, and to determine a fingerprint of the differentiated gas components. A reaction section and a vacuum section may be used for waste consumption and/or absorption.

Abstract: A micro-fabricated chromatography column (70) which is particularly well-suited to the surface well-site and/or the downhole analysis of subterranean reservoir fluids in oilfield or gasfield applications (but which may also be used in non-oilfield or non-gasfield situations) is described. This micro-fabricated column integrates a micro-structured substrate (50), such as a silicon substrate, with a stationary phase material (66) deposited by sputtering as a coating in a microchannel (56) in the substrate (50). Benefits of the presently claimed and disclosed inventive concept(s) include enhanced separation of alkanes and isomers, particularly below hexane (i.e., below C6 as well as the separation of carbon dioxide, hydrogen sulfide, and water and other substances present in reservoir fluids, such as natural gas.

Abstract: Disclosed herein are a multi-layer chip for gas chromatography and a method of fabricating the multi-layer chip. The multi-layer chip is fabricated by: forming fine channels at the same positions of a plurality of substrates using only a single photo mask and an alignment key; and stacking the substrates. That is, the multi-layer chip can be fabricated by a simple method, and the total length of the fine channels can be increase without a limit by stacking more substrates. In addition, layers of the substrates can be coated with different stationary phases, and a temperature control device can be attached to heat transfer contact portions of the multi-layer chip for controlling the temperature of the multi-layer chip rapidly and precisely. Therefore, the multi-layer chip may be useful for high-separability gas chromatography to separate and analyze an infinitesimal amount of a sample.

Abstract: A system for analyzing a gas mixture, including at least one chromatography column, a mechanism injecting the mixture into the column, and a mechanism detecting compound(s) forming the gas mixture, the detection mechanism including at least one detector of nanosensor type of an outlet of the column and a detector of nanosensor type in the column, capable of detecting passage of the compounds. It is then possible to determine the velocity of each of the compounds within the system.

Abstract: An apparatus for detecting a presence of at least one analyte in a gas sample. The apparatus comprises a pump for drawing a gas sample from an ambient air, a passage having first and second ends, a chamber connected to the first end and containing a concentrating element for collecting at least one analyte from the gas sample, a chromatographic separator connected to a second end of the passage, and a gas source for streaming a carrier gas via the chamber to transfer the at least one analyte toward at least one chemical detector, via the chromatographic separator, in a first direction. The pump draws the gas sample via the chamber in a second direction and the first and second directions are substantially opposing to one another.

Abstract: A method and system for rapid determination of a hydrocarbon type composition, such as crude oils and fractions thereof, and s obtaining the information necessary to assess the yield of commercially valuable fuel and lube oil fractions in a single process, variations of the method and system use Gas Chromatography-FID/Mass Spectrometry and other features, including an auto sampler, a wall coated capillary column, a temperature programmable injector, and a data processing system for compiling and processing the experimental data. The system and method further include a computer system with application software or other processing mechanism and optionally a communication network. One variation provides a graphical user interface for the entry of data and for displaying information, such as in a graphical manner, to show the relationship of various determined outputs and results.

Abstract: The invention is a chromatography apparatus which comprises at least one capillary column, which has a coil assembly of column material and a small diameter wire coated with an electrically insulating high temperature material encased within a high temperature sheath. The small diameter wire is at least one electrically conductive element co-linear with the column material. Also provided is means for directly resistively heating the at least one capillary column, and means for controlling the temperature of the capillary column. Additionally, the apparatus includes an oxygen gas containing inlet, a hydrogen inlet, an analyte port and a flame region, oxygen delivery means for delivering oxygen through the oxygen inlet to the flame region, a hydrogen and analyte delivery system for delivering hydrogen and analyte to the flame region, and a detector arranged to detect flame emission.

Abstract: A gas chromatography inlet liner comprises a glass tube formed by a glass wall, the glass wall having pore channels formed therein, and an indicator present in the pore channels in at least part of the inlet liner. The indicator may be any element, compound, dopant, or mixture additive that modifies color or transparency of the inlet liner.