A method of screening a hydrocarbon stream for potential toxicological hazards. The method involves providing a hydrocarbon stream; conducting 2-dimensional gas chromatography (2D-GC) analysis to quantify saturates and aromatic distribution in the hydrocarbon stream; identifying 2-8 ring aromatic distribution and weight percentage of 2-8 ring aromatic molecules in the hydrocarbon stream from the 2D-GC analysis; relating the weight percentage of 2-8 ring aromatic molecules in the hydrocarbon stream from the 2D-GC analysis to a mutagenicity index (MI), in which the MI is determined in accordance with ASTM Standard Method E 1687; and assessing a potential toxicological hazard of the hydrocarbon stream based on the weight percentage of 2-8 ring aromatic molecules in the hydrocarbon stream from the 2D-GC analysis and a MI threshold value. The 2-8 ring aromatic distribution preferably includes 3-6 ring aromatics, more preferably 3.5-5.5 ring aromatics. The 2-8 ring aromatic distribution includes mono alkylated and multi alkylated aromatic molecules.

In a method for processing successive fluidic sample portions provided by a sample source, sample reception volumes are filled successively temporarily with at least a respective one of the sample sections, and the sample sections are emptied successively out of the sample reception volumes in such a way, that, while emptying, it is avoided to bring two respective ones of the sample sections, which have not left the sample source directly adjacent to one another, in contact with one another.

This tool utilizes orthogonality concepts used for analytical chromatography and apply them to chromatography for downstream processing applications utilizing a small set of product-agnostic, optimally orthogonal resins with which most separations (capture or polishing) can be accomplished. Libraries of components for separation mediums are provided. The library of components is administered to the separation mediums and combination of the separation mediums at varying pHs, and the separability and orthogonality of each is quantified. The separability is a measure of a probability that the separation mediums will separate a pair of components, whereas the orthogonality is a measure of the enhancement in separability upon addition of another separation medium. By identifying those combinations of separation mediums that not only provide advantageous separability, but also high orthogonality, sets of separation mediums can be more easily provided or wholly designed for use in processing applications.

A gas chromatographic method for detecting a marker compound in a fuel by (a) introducing a sample of fuel into a first capillary column coated with a stationary phase based on polydimethylsiloxane and allowing the sample to flow through the first column to produce a first effluent; (b) allowing the first effluent to pass through a detector and identifying a retention time range in it which includes a retention time of the marker compound; (c) introducing only a portion of the first effluent stream which is within the retention time range into a second capillary column coated with either (i) an ionic sorbent or (ii) a polyethylene glycol, and allowing said portion to flow through the second capillary column to produce a second effluent stream; and (d) allowing the second effluent to pass through a detector; wherein the marker compound has formula Ar(R.sup.2).sub.m(OR.sup.1).sub.n and is present in the fuel at a level from 0.01 ppm to 100 ppm.

Described is a rotary valve that includes a stator, a rotor and a plurality of sample channels. The stator includes a stator surface having an inlet port, an outlet port and a plurality of selectable ports. The rotor includes a rotor surface having a first rotor channel and a second rotor channel. The rotor is configurable in a plurality of rotor positions, each of which couples the inlet port to one of the selectable ports through the first rotor channel and couples the outlet port to another one of the selectable ports through the second rotor channel. The two selectable ports are coupled to each other through one of the sample channels. The rotor has a bypass state defined by a rotor position, or angular range of rotor positions, at which the inlet port is coupled to the outlet port through the second rotor channel.

A multidimensional chromatographic assembly includes a chromatographic medium selector module, which receives a sample from an injector module and moves the sample through one of at least two chromatographic media of a chromatographic medium module using at least one eluent from at least one fluid moving module. At least a portion of the sample is re-circulated through the same or the second chromatographic medium using a multi-configuration fluid diverting module, which isolates a selected portion of the chromatographed eluent containing at least a portion of the sample in at least one fluid holding compartment and later moves the isolated portion through one of the chromatographic media in an iterative manner until all attributes of the isolated portion in question are analyzed. A detector module, which is located between the chromatographic medium selector module and the fluid diverting module, acquires data each time a portion of the sample passes through the detector module and provides data for a multidimensional chromatogram. The configurable portion (the rotor) of the fluid diverting module comprises movable flow-paths with two termini, which lie on a circular perimeter, concentric to the axis of rotation of the rotor, on the interfacial plane where the rotor meets the stationary portion of the fluid diverting module (the stator), and a connecting coplanar groove, spatial disposition of which is either concave or convex to the circular perimeter with only the termini intercepting the perimeter. The entire assembly is controlled by a controller, which receives data from the detector module and sends instructions to all modules during the multidimensional analysis with or without human intervention.

A sample separation apparatus includes a first-dimension separation unit for separating the fluidic sample, having a first-dimension outlet for outputting the fluidic sample or fractions thereof, and a second-dimension separation unit for further separating the fluidic sample or fractions thereof. The second-dimension separation unit has a second-dimension inlet fluidically coupled to the first-dimension outlet. A modulation unit, coupled between the first-dimension outlet and the second-dimension inlet at a first coupling point, is configured for withdrawing fluid from the first coupling point and for ejecting fluid into the first coupling point. A second-dimension fluid drive is coupled to a second coupling point located between the first-dimension outlet and the second-dimension inlet and downstream from the first coupling point. The second-dimension fluid drive is configured for generating a fluid flow for driving at least part of the fluidic sample after treatment by the first-dimension separation unit through the second-dimension separation unit.

Exemplary embodiments eliminate the need for column ovens in serial column chromatography arrangements and systems by using insulated sleeves. The insulated sleeves may encase individual chromatography columns or clusters of chromatography columns. The use of the insulated sleeves allows the chromatography columns to be positioned in close proximity to each other. This may decrease the overall size of a serial column chromatography arrangement and may reduce costs by not requiring the column ovens.

A sample separation apparatus for separating a fluidic sample includes an initial dimension sample separation device configured for separating the fluidic sample, a subsequent dimension sample separation device configured for further separating separated fluidic sample received from the initial dimension sample separation device, a purity detector configured for detecting information indicative of a purity of a portion of the fluidic sample which has been separated by the initial dimension sample separation device, and a control unit configured for controlling, depending on the detected information, whether or not further separation of the portion of the fluidic sample which has been separated by the initial dimension sample separation device is carried out by the subsequent dimension sample separation device.

Described herein are systems and methods used for carrying out a two-dimensional liquid chromatography process using size exclusion chromatography as a first dimension.