Semiquantitative Screening of THC Analogues by Silica Gel TLC with an Ag(I) Retention Zone and Chromogenic Smartphone Detection.

With the ever-evolving cannabis industry, low-cost and high-throughput analytical methods for cannabinoids are urgently needed. Normally, (potentially) psychoactive cannabinoids, typically represented by Δ9-tetrahydrocannabinol (Δ9-THC), and nonpsychoactive cannabinoids with therapeutic benefits, typically represented by cannabidiol (CBD), are the target analytes. Structurally, the former (tetrahydrocannabinolic acid (THCA), cannabinol (CBN), and THC) have one olefinic double bond and the latter (cannabidiolic acid (CBDA), cannabigerol (CBG), and CBD) have two, which results in different affinities toward Ag(I) ions.

Ionization of glycans from alkali metal salt-impregnated paper.

Ambient ionization of glycans is simply and efficiently achieved by spraying from an alkali metal salt-impregnated paper surface. Monosaccharides, oligosaccharides and ring glycans easily form abundant alkali metal adduct ions, and give simple and clean high-quality mass spectra. The enhancement is specific for glycans, compared to a wide variety of non-glycan compounds present in a matrix.

Rapid analysis of anionic and cationic surfactants in water by paper spray mass spectrometry.

The discharge of wastewater containing surfactants and other industrial pollutants is contaminating the world's water resources which should be taken seriously. This paper describes a paper spray mass spectrometric (PS-MS) method for rapid and quantitative analysis of anionic and cationic surfactants in water samples. Eight cationic surfactants and four anionic surfactants can be simultaneously determined in positive or negative mode without sample pretreatment and chromatographic separation.

Synthesis of a poly(sulfobetaine-co-polyhedral oligomeric silsesquioxane) hybrid monolith via an in-situ ring opening quaternization for use in hydrophilic interaction capillary liquid chromatography.

An in-situ approach is described for synthesis of poly(sulfobetaine-co-polyhedral oligomeric silsesquioxane) [poly(sulfobetaine-co-POSS)] that can be used in a hybrid monolithic column as a hydrophilic liquid chromatography (HILIC) stationary phase. Synthesis involves (a) radical polymerization of octa(propyl methacrylate)-polyhedral oligomeric silsesquioxane (MA-POSS) and organic monomers such as dimethylaminopropyl methacrylate or vinyl imidazole, and (b) in-situ ring-opening quaternization between 1,4-butane sultone and the organic monomers. The sulfobetaine groups are generated in-situ monolith.

Fluoro-functionalized paper-based solid-phase extraction for analysis of perfluorinated compounds by high-performance liquid chromatography coupled with electrospray ionization-tandem mass spectrometry.

Fluoro-functionalized paper was prepared and applied in solid phase extraction (SPE) for the analysis of trace-level perfluorinated compounds (PFCs). The proposed fluoro-functionalized paper-based solid-phase extraction (Fp-SPE) exhibits significant advantages for sample preparation, such as the biodegradability of paper-based adsorbent, simple manipulation and low cost. Owing to the fluorous affinity, the Fp-SPE technique with high sensitivity and high selectivity is more suitable for the selective enrichment of fluorine-containing molecules from the background of non-fluorinated organic compounds in a real water sample.

Rapid quantitative analysis of ginkgo flavonoids using paper spray mass spectrometry.

In this work, a method for the rapid and reliable analysis of ginkgo flavonoids was developed by using paper spray mass spectrometry (PS-MS) assisted by microwave-assisted hydrolysis (MAH). Kaempferol-D, quercetin-D, and isorhamnetin-D were used as internal standards (IS). Samples analyses were completed by simply treating with extraction, MAH, dilution, and quantitative analysis by PS-MS.

Rapid analysis of benzoic acid and vitamin C in beverages by paper spray mass spectrometry.

A paper spray mass spectrometry (PS-MS) method has been developed for the rapid quantification of benzoic acid (BA) and vitamin C (VC) in beverages. Using BA-d5 as an internal standard (IS) to analyze BA and VC, the calibration curves ranged from 0.3 to 100 μg/mL for BA and 1 to 100 μg/mL for VC, the linearity was 0.

Immobilization of enzymes at high load/activity by aqueous electrodeposition of enzyme-tethered chitosan for highly sensitive amperometric biosensing.

Electrodeposition has been so widely used to immobilize biomacromolecules, and it is always an important topic to increase the load and activity of the immobilized biomacromolecules. We report here on a new, simple and rather universal method for the highly efficient immobilization of enzymes by aqueous electrodeposition of enzyme-tethered chitosan (CS) for sensitive amperometric biosensing. Glucose oxidase (GOx) is chosen here to examine the proposed protocol in detail.

Electrochemical quartz crystal microbalance study of covalent tethering of carboxylated thiol to polyaniline for electrocatalyzed oxidation of ascorbic acid in neutral aqueous solution.

The electrochemical quartz crystal microbalance (EQCM) was used to study the electrosyntheses and electrochemical properties of two kinds of polyaniline (PANI)-thiol composite films in aqueous solutions, which were prepared by covalent binding of a thiol to the oxidized forms of PANI (PANI(post)-thiol, protocol A), and electropolymerization of aniline in the presence of a thiol (PANI(poly)-thiol, protocol B), respectively. The thiols involved were mercaptosuccinic acid (MSA), thioglycolic acid (TGA) and beta-mercaptoethanol (ME). The PANI(post)-thiol binding processes were monitored in situ with the EQCM, giving molar binding ratios (r, thiol vs.