A chromatography analysis apparatus (30) comprises: a fractionation device (32) for receiving a sample, the fractionation device (32) defining a sample flow path that includes a guard column; and a fractionation output analyser (34), wherein a fractionation output of the guard column is provided to an input of the fractionation output analyser (34) for enabling subsequent analysis of the fractionation output by the fractionation output analyser (34).

Provided is a guard column including a filling part having a length of 2.0 cm to 3.5 cm formed of a filler, in which the filler is made of porous silica gel having a hydrophilized surface and an average particle size of 1.5 μm to 2.5 μm, and a pressure difference when an aqueous solution is fed at a linear flow rate of 2.1 cm/min is 4.0 MPa or more.

Provided is a guard column including a filling part having a length of 2.0 cm to 3.5 cm formed of a filler, in which the filler is made of porous silica gel having a hydrophilized surface and an average particle size of 1.5 μm to 2.5 μm, and a pressure difference when an aqueous solution is fed at a linear flow rate of 2.1 cm/min is 4.0 MPa or more.

Systems and methods for concentrating an analyte preparatory to analysis thereof include processing the effluent of an analyte concentrator to produce an eluent for eluting an analyte retained in the same or separate concentrator, and systems implementing the same. The analyte concentrator system connects the effluent outlet of an analyte concentrator column to an eluent generation module such that the substantially analyte-free effluent discharged from the analyte concentrator column passes fluidly into the eluent generation module. Eluent generated from the substantially analyte-free effluent in the eluent generation module is likewise substantially free of the analyte. The systems and methods can minimize and/or (substantially) eliminate background signal during analysis of the concentrated analyte.

In various aspects, the present disclosure pertains to materials (e.g., kits, column assemblies, liquid chromatography systems, etc.) methods for performing liquid chromatography that employ a first column (e.g., a trapping column) and a second column (e.g., an analytical column). The first column comprises a first chromatographic material having a first chromatographic surface that comprises first hydrophobic surface groups and first ionizable surface groups having a first pKa value. The second column comprises a second chromatographic material having a second chromatographic surface that comprises second hydrophobic surface groups and (a) permanently ionized surface groups or (b) second ionizable surface groups having a second pKa value. The first hydrophobic surface groups have a hydrophobicity that is less than a hydrophobicity of the second hydrophobic surface groups. Moreover, where the second chromatographic surface comprises second ionizable surface groups, the first pKa value may differ from the second pKa value by 1-12 units.

The disclosed system and method improve measurement of trace volatile chemicals, such as by Gas Chromatography (GC) and Gas Chromatography/Mass Spectrometry (GCMS). A first trapping system can include a plurality of capillary columns in series and a focusing column fluidly coupled to a first detector. The first trapping system can retain and separate compounds in a sample, including C3 hydrocarbons and compounds heavier than C3 hydrocarbons (e.g., up to C12 hydrocarbons, or compounds having a boiling point around 250° C.), and can transfer the compounds from the focusing column to the first detector. A second trapping system can receive compounds that the first trapping system does not retain, and can include a packed trap, a polar column and a PLOT column fluidly coupled to one or more second detectors. The second trapping system can remove water from the sample and can separate and detect compounds including C2 hydrocarbons and Formaldehyde.

A method for reducing the variability, as measured by relative standard deviation (RSD), of an analytical testing technique is provided. This improvement in RSD improves the confidence in the values obtained during field testing. The method includes incorporating a focusing agent into the sampling media, which permits providing sampling media such as thermal desorption tubes preloaded with the focusing agent.

A microscale collector and injector device comprises a microscale passive pre-concentrator (μPP) and a microscale progressively-heated injector (μPHI). The μPP devices comprises first and second substrate portions, a first collection material, a μPP heater, and an outlet. The first substrate portion defines an array of microscale diffusion channels. The first and second substrate portions cooperate to define a first compartment in fluid communication with the diffusion channels. The first collection material is disposed within the first compartment, at least partially surrounding the outlet. The μPP heater is disposed in thermal communication with the second substrate portion. The μPHI device comprises third and fourth substrate portions, a second collection material, and a plurality of μPHI heaters. The third and fourth substrate portions cooperate to define a second compartment. The second collection material is disposed within the second compartment. The μPHI heaters are disposed in thermal communication with the second compartment.

A microscale collector and injector device comprises a microscale passive pre-concentrator (μPP) and a microscale progressively-heated injector (μPHI). The μPP devices comprises first and second substrate portions, a first collection material, a μPP heater, and an outlet. The first substrate portion defines an array of microscale diffusion channels. The first and second substrate portions cooperate to define a first compartment in fluid communication with the diffusion channels. The first collection material is disposed within the first compartment, at least partially surrounding the outlet. The μPP heater is disposed in thermal communication with the second substrate portion. The μPHI device comprises third and fourth substrate portions, a second collection material, and a plurality of μPHI heaters. The third and fourth substrate portions cooperate to define a second compartment. The second collection material is disposed within the second compartment. The μPHI heaters are disposed in thermal communication with the second compartment.

A method for reducing the variability, as measured by relative standard deviation (RSD), of an analytical testing technique is provided. This improvement in RSD improves the confidence in the values obtained during field testing. The method includes incorporating a focusing agent into the sampling media, which permits providing sampling media such as thermal desorption tubes preloaded with the focusing agent.