The invention relates to the detection of non-metabolized vitamin D. In a particular aspect, the invention relates to methods for detecting underivatized non-metabolized vitamin D by mass spectrometry.

In various aspects, the present disclosure pertains to methods of performing a sample enrichment procedure, which comprise: adding a sample fluid that comprises at least one phospholipid and at least one target analyte to a sorbent that comprises a hydrophobic component and a cation exchange component, thereby resulting in sorbent with bound phospholipid and bound target analyte; adding an aqueous solution comprising an acidic compound and a salt; adding an organic solution to the sorbent thereby desorbing at least a portion of the bound phospholipid from the sorbent; and adding an elution solution to the sorbent, thereby desorbing at least a portion of the bound target analyte from the sorbent and forming a solution of the target analyte in the elution solution. In other aspects, the present disclosure pertains to kits, which may be used in conjunction with such methods.

A sample extraction device and a desorption device for use in gas chromatography (GC), gas chromatography-mass spectrometry (GCMS), liquid chromatography (LC), and/or liquid chromatography-mass spectrometry (LCMS) are disclosed. In some examples, the sample extraction device includes a lower chamber holding a sorbent. The sample extraction device can extract sample headspace gas from a sample vial by placing the sorbent inside the vial and creating a vacuum to increase recovery of low volatility compounds, for example. Once the sample has been collected, the sample extraction device can be inserted into a desorption device. The desorption device can control the flow of a carrier fluid (e.g., a liquid or a gas) through the sorbent containing the sample and into a pre-column and/or a primary column of a chemical analysis device for performing GC, GCMS, LC, LCMS, and/or some other chemical analysis process.

Photo-initiated polymeric ionic liquids, methods of making and methods of using the same are disclosed. A preferred embodiment for making a photo-initiated polymeric ionic liquid (P-PIL) coated support, comprises: mixing at least one ionic liquid (IL) monomer with at least one photo-initiator; at least partially coating a support with the mixture; and exposing the coated support to UV light to form a photo-initiated polymeric ionic liquid (P-PIL) coated support.

The present invention provides a preprocessing device of a more compact structure, and an analysis system provided with the same. A preprocessing device (1) includes a container holding section (12), a filtration port (30), and a transport arm (24). The container holding section (12) holds a separation container (50) and a collection container (54). The filtration port (30) separates a sample by applying pressure to a sample in the separation container (50). The transport arm (24) transports the separation container (50) and the collection container (54) held by the container holding section (12) from a predetermined transport position. The container holding section (12) holds the separation container (50) and the collection container (54) in an annular or arch-shaped holding region formed on an outer circumference of the filtration port (30), and sequentially moves the separation container (50) and the collection container (54) to the transport position by shifting the separation container (50) and the collection container (54) in the circumferential direction of the holding region.

Techniques disclosed herein can improve the extraction of chemicals prior to analysis by GC or GCMS. A liquid or solid sample can be placed in a sample container of a closed system under vacuum that further includes a sample extraction device. The assembly can be placed in a 3-zone heater that can separately control the temperature of the bottom of the sample container, the top of the sample container, and the sample extraction device. Vapor flux from the bottom of the sample container into the headspace of the sample container can deliver compounds of interest to the sample extraction device, whereas matrix compounds can re-condense in the headspace of the sample container to avoid delivery to the sample extraction device. Extraction can continue until substantial transfer of compounds of interest to the sorbent occurs, followed by thermal desorption of the extract into a GCMS for analysis.

Determination of Analytes in a Sample Matrix by Solvent Extraction A method for the assay of one or more analytes in a sample matrix comprising the steps of: performing analyte extraction on the sample matrix, said analyte extraction comprising combining the sample matrix with a solvent for an extraction period which is less than that required for reaching equilibrium; and separating the analyte containing solvent from the sample matrix; next measuring a level of analyte present in the separated solvent; and then applying in a computer a calibration by which is established a mathematical relationship between levels of analyte extracted from each of a plurality of reference samples by means of the process employed above in the extraction for the sample matrix and a reference value of the levels of analyte for each reference sample to thereby derive a measure of the level of analyte in the sample matrix. Specifically a method to determine the amount of mycotoxins in cereal grain, especially OTA (ochratoxin A) and DON (deoxynivalenol) by mixing with a solvent comprising water alcohol mixture, with 20-40% ethanol by volume.

Provided are methods for isolating biomolecules, such as nucleic acids and proteins, from a sample using a silica-containing surface and/or a high salt, low pH buffer.

Disclosed herein is a system for desorbing and detecting an analyte sorbed on a solid phase microextraction (SPME) device. The system includes a desorption chamber sized to accept the SPME device while defining a void volume of less than about 50 μL; a flow injector in fluid connection with the desorption chamber, the desorption chamber and the flow injector being fluidly connected by at least a flow-insulating fluid connector; a solvent source in fluid connection with the flow injector; and a fluid switch that: in a desorption position, allows the solvent to be sprayed from the flow injector while flow-insulating any desorption solution in the desorption chamber, and in an detecting position, turns off the solvent source while maintaining the fluid connection between the flow injector and the desorption chamber, transferring the desorption solution through the flow-insulating fluid connector to the flow injector as a substantially undiluted plug of liquid.

Disclosed is a device for a solid phase extraction comprising two or more of the sorbents to remove phospholipids and salts from a sample, to thereby eliminate matrix effects during mass spectrometry analysis. In particular, the sorbents includes at least one sorbent which is water-wettable and contains at least one hydrophobic component and at least one hydrophilic component and at least one of sorbent having a specific affinity for a matrix interference like phospholipids. Further disclosed is a method using the device of the present invention.