The measurement of glutaraldehyde-based biocides in seawater without the use of a derivatization agent. The measurement of glutaraldehyde-based biocides in seawater may be performed without additional components to reduce background interferences. The concentration of a glutaraldehyde-based biocides in a seawater sample is determined using reversed phase liquid chromatography and a gradient mobile phase of acetonitrile and deionized water. Systems for determining the concentration of glutaraldehyde-based biocide in a seawater injection system are also provided.

This disclosure provides liquid chromatography tandem mass spectrometer (LC-MS/MS) methods and systems for detecting low levels of pesticides and mycotoxins in a test sample. In the disclosed methods and systems, oxalic acid is added to a mobile phase composition of a reverse phase chromatographic separation column. This addition improves the signal for certain pesticides and mycotoxins by a factor of from 1.5 to 9, improving their detection limits in a variety of test samples.

The invention relates to a method for manufacturing a multicapillary packing for an exchange of material including the formation, by a 3D printing method, of a monolith having a porous mass through which a plurality of parallel channels passes, opening on an inlet face and an outlet face of the packing, the 3D printing method being chosen among: selective laser sintering, molten wire deposition, stereolithography, binder spraying and spraying of material, the porous mass being suitable for allowing the diffusion of material to be exchanged between the channels.

The measurement of glutaraldehyde-based biocides in seawater without the use of a derivatization agent. The measurement of glutaraldehyde-based biocides in seawater may be performed without additional components to reduce background interferences. The concentration of a glutaraldehyde-based biocides in a seawater sample is determined using reversed phase liquid chromatography and a gradient mobile phase of acetonitrile and deionized water. Systems for determining the concentration of glutaraldehyde-based biocide in a seawater injection system are also provided.

The invention relates to an immunochromatographic device which contains a nitrous acid compound and an organic acid or an organic acid derivative and which is for detecting a detection target in an analyte wherein a sample droplet-receiving member, a labeling substance-holding member, a chromatography medium member and an absorption member are arranged in a manner that a sample develops in this order and wherein a part containing the nitrous acid compound and a part containing the organic acid or the like are at upstream positions from the labeling substance-containing part, and the part containing the nitrous acid compound and the part containing the organic acid or the like are not substantially in contact with each other in the thickness direction.

In accordance with embodiments of the present invention, a terpene-rich sample is prepared for terpene analysis using liquid chromatography via an extraction method that takes little time, uses minimal external equipment, and permits direct injection of extracted terpenes into a liquid chromatography instrument for analysis. An embodiment of the invention involves preparing a terpene-containing sample for analysis by liquid chromatography by liquid extraction; heating the liquid extract in a vial that contains a filter medium or solvent; collecting the terpenes in the medium by the vapor pressure forced through the filter from heating; and eluting the collected terpenes into a vial or directly into a chromatography injector.

In accordance with embodiments of the present invention, a terpene-rich sample is prepared for terpene analysis using liquid chromatography via an extraction method that takes little time, uses minimal external equipment, and permits direct injection of extracted terpenes into a liquid chromatography instrument for analysis. An embodiment of the invention involves preparing a terpene-containing sample for analysis by liquid chromatography by liquid extraction; heating the liquid extract in a vial that contains a filter medium or solvent; collecting the terpenes in the medium by the vapor pressure forced through the filter from heating; and eluting the collected terpenes into a vial or directly into a chromatography injector.

Provided are a novel chitosan compound represented by Formula (I) and a separating agent for optical isomers. In Formula (I), each R is independently a group represented by Formula (II) or a group represented by Formula (III); R.sup.a is an alkyl group having from 1 to 5 carbons or an alkyl group having from 3 to 5 carbons and having a branched chain; and n is an integer of 5 or greater; and in Formulas (II) and (III), each R.sup.b is independently an unsubstituted phenyl group, a phenyl group having a substituent, an unsubstituted cylohexyl group, or a cyclohexyl group having a substituent, and each of the substituent is independently an alkyl group having from 1 to 5 carbons, or a halogen.

Provided are a novel chitosan compound represented by Formula (I) and a separating agent for optical isomers. In Formula (I), each R is independently a group represented by Formula (II) or a group represented by Formula (III); R.sup.a is an alkyl group having from 1 to 5 carbons or an alkyl group having from 3 to 5 carbons and having a branched chain; and n is an integer of 5 or greater; and in Formulas (II) and (III), each R.sup.b is independently an unsubstituted phenyl group, a phenyl group having a substituent, an unsubstituted cylohexyl group, or a cyclohexyl group having a substituent, and each of the substituent is independently an alkyl group having from 1 to 5 carbons, or a halogen.

A chromatography method in which a gaseous, liquid or supercritical mobile phase containing species to be separated is circulated through a packing. The packing includes a plurality of capillary ducts extending in the packing between an upstream face through which the mobile phase enters the packing and a downstream face through which the mobile phase leaves the packing. A continuous medium permeable to molecular diffusion extends between the ducts, including a porous organic gel or an organic liquid with at least one network of connected pores, the size of which is greater than two times the molecular diameter of at least one species to be separated. The at least one species has a diffusive path between the ducts.