Determination of copolymer compositions in polyhydroxyalkanoates using H benchtop nuclear magnetic resonance spectroscopy.

Continuous research into polyhydroxyalkanoates (PHAs), biodegradable polymers which can be produced by, and harvested from, various bacteria has led to more cost-effective ways of isolating and commercializing them. As bio-based polymers, PHAs can be transformed into compostable bioplastics and utilized for a variety of applications. Often isolated as copolymers, the monomeric ratio compositions of these products greatly affect both the properties and consequently, possible end uses of these products.

Benchtop nuclear magnetic resonance performance evaluation according to ASTM E691-22 on a population of instruments: Molar substitution determination in hydroxypropyl betadex as a case study for use in quality control environments.

The inclusion of quantitative nuclear magnetic resonance (qNMR) spectroscopy in industry has historically been stifled by a lack of accessibility, caused in-part by the large costs of traditional high-field spectrometers, the maintenance required for these, and the expertise necessary to manage and use them. In recent years, the emergence of benchtop NMR technology, an accessible, affordable, and automatable alternative, has led to a more feasible incorporation of NMR into quality control spaces, an area traditionally reserved for other techniques such as gas chromatography and liquid chromatography, which are routinely combined with detection techniques such as mass spectrometry. While these techniques are commonly used in analyzer-type applications using gold standard methods of analysis, wherein an instrument is dedicated to performing specific assays, this remains uncommon for NMR.

3,4-Methylenedioxymethamphetamine quantification via benchtop H qNMR spectroscopy: Method validation and its application to ecstasy tablets collected at music festivals.

We describe a method validation for the quantification of 3,4-methylenedioxymethamphetamine (MDMA) in tablets based on the United Nations Office on Drugs and Crime (UNODC) guideline for quantitative Nuclear Magnetic Resonance analysis (qNMR). qNMR experiments were carried out on a 60 MHz benchtop NMR spectrometer employing ethylene carbonate as an internal calibrant. A series of 'ecstasy' tablets seized at music events were quantified and the results discussed regarding their within-batch variation and yearly median dose.

Identification of seven psychedelic 2,5-dimethoxy-phenylethyl-amine-based designer drugs via benchtop H nuclear magnetic resonance spectroscopy.

The dissemination of spectral information of new psychoactive substances (NPS) acquired on benchtop nuclear magnetic resonance (NMR) spectrometers is of high importance considering the emerging application of such portable and accessible instruments in forensic analyses. Seven members of the 2C-X series (2C-B, 2C-C, 2C-D, 2C-E, 2C-P, 2C-T2, and 2C-T7) of NPS were analyzed via 60 MHz H benchtop NMR spectroscopy and their molecular structural relations are discussed with respect to the observed proton NMR spectra.

Lithium-7 qNMR as a method to quantify lithium content in brines using benchtop NMR.

A novel Li quantitative NMR (qNMR) method to analyze lithium was developed to determine the lithium content in real brine samples using benchtop NMR instruments. The method was validated, and limits of detection and quantification of 40 and 100 ppm, respectively, were determined. Linearity, precision, and bias were also experimentally determined, and the results are presented herein.

Quantitative analysis of cannabinoids using benchtop NMR instruments.

The quantification of cannabinoids is an essential part of cannabis profiling and testing, whether for medical or recreational use. As regulatory bodies continue to increase testing requirements for these products, it is crucial that alternative and effective analytical methods be developed. Herein, we describe the use of benchtop NMR instruments for the quantification of Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD) in a variety of cannabis concentrates and compare the values to those obtained using HPLC, the most common approach for the quantification of cannabinoids.

Synthesis and characterization of elusive cyclo-di- and -tri-phosphino-1,3-diphosphonium salts: fundamental frameworks in catena-organophosphorus chemistry.

Reaction of a cyclophosphinophosphonium cation with neat MeOTf represents a general and high-yield synthetic approach to dications enabling the isolation of the first derivatives of 2,4,5-triphosphino-1,3-diphosphonium as bis-triflate salts.

Prototypical phosphorus analogues of ethane: general and versatile synthetic approaches to hexaalkylated P-P diphosphonium cations.

Versatile alkylation reactions give access to symmetric, homoleptic nonsymmetric, and heteroleptic symmetric hexaalkylated 1,2-diphosphonium derivatives as bottleable salts in high yields. A series of 1,2-diphosphonium salts has been isolated and characterized, representing prototypical phosphorus analogues of ethane. Additionally, the solid-state structures for four derivatives have been determined crystallographically.

Cyclotetraphosphinophosphonium ions: synthesis, structures, and pseudorotation.

The first derivatives of catenated cyclotetraphosphinophosphonium cations, [(PhP)4PPhMe]+ (8a), [(MeP)4PMe2]+ (8b), [(CyP)4PPh2]+ (8d), [(CyP)4PMe2]+ (8e), [(PhP)4PPh2]+ (8f), [(PhP)4PMe2]+ (8g), are synthesized as trifluoromethanesulfonate (triflate, OSO2CF3-) salts through the reaction of cyclopentaphosphines (PhP)5 (4a) or (MeP)5 (4b) with methyl triflate (MeOTf) or by a net phosphenium ion [PR2+, R = Ph, Me; from R2PCl and trimethylsilyltriflate (Me3SiOTf)] insertion into the P-P bond of either cyclotetraphosphine (CyP)4 (3c) or cyclopentaphosphines (PhP)5 (4a) or (MeP)5 (4b). Although more conveniently prepared from 4a, compound 8a[OTf] can also be formed from (PhP)4 (3a) and MeOTf, and derivatives 8f[OTf] and 8g[OTf] are also accessible through reactions of 3a and R2PCl/Me3SiOTf with R = Ph or Me, respectively. A tetrachlorogallate salt of [(PhP)4PPhtBu]+ (8c) has been synthesized by alkylation of 4a with tBuCl/GaCl3.

2,2'-Disubstituted F12binaphthyl derivatives: stannanes, boranes, and (R)-F12BINOL.

2,2'-Distannyl derivatives of dodecafluorobinaphthalene are converted to a novel D2 symmetric borane dimer, which can be oxidized to (+)-F12BINOL; resolution using (S)-acetoxypropanoyl chloride affords enantiopure material.