Comprehensive cannabinoid profiling of acid-treated CBD samples and Δ8-THC-infused edibles.

Δ8-Tetrahydrocannabinol (Δ8-THC) is increasingly popular as a controversial substitute for Δ9-tetrahydrocannabinol (Δ9-THC) in cannabinoid-infused edibles. Δ8-THC is prepared from cannabidiol (CBD) by treatment with acids. Side products including Δ9-THC and other isomers that might end up in Δ8-THC edibles are less studied. In this paper, three orthogonal methods, namely reversed-phase (RP)-UHPLC-DAD/HRMS, normal-phase/argentation (silica-Ag(I))-HPLC-DAD/MS, and GC-FID/MS were developed for analysis of cannabinoid isomers, namely Δ8-THC, Δ9-THC, CBD, Δ8-iso-THC, Δ(4)8-iso-THC, and hydrated THC isomers. Eight acid-treated CBD mixtures contained various amounts of Δ8-THC (0-89%, w/w%), high levels of Δ9-THC (up to 49%), Δ8-isoTHC (up to 55%), Δ(4)8-iso-THC (up to 17%), and three hydrated THC isomers. Commercial Δ8-THC gummies were also analyzed, and issues like overclaimed Δ8-THC, excessive Δ9-THC, undeclared Δ8-iso-THC, and Δ(4)8-iso-THC were found. These findings highlight the urgency of improving regulations towards converting CBD to Δ8-THC for use as food ingredients.

Leveraging 3D printing to enhance mass spectrometry: A review.

The use of 3D printing in the chemical and analytical sciences has gained a lot of momentum in recent years. Some of the earliest publications detailed 3D-printed interfaces for mass spectrometry, which is an evolving family of powerful detection techniques. Since then, the application of 3D printing for enhancing mass spectrometry has significantly diversified, with important reasons for its application including flexible integration of different parts or devices, fast customization of setups, additional functionality, portability, cost-effectiveness, and user-friendliness. Moreover, computer-aided design (CAD) and 3D printing enables the rapid and wide distribution of scientific and engineering knowledge. 3D printers allow fast prototyping with constantly increasing resolution in a broad range of materials using different fabrication principles. Moreover, 3D printing has proven its value in the development of novel technologies for multiple analytical applications such as online and offline sample preparation, ionization, ion transport, and developing interfaces for the mass spectrometer. Additionally, 3D-printed devices are often used for the protection of more fragile elements of a sample preparation system in a customized fashion, and allow the embedding of external components into an integrated system for mass spectrometric analysis. This review comprehensively addresses these developments, since their introduction in 2013. Moreover, the challenges and choices with respect to the selection of the most appropriate printing process in combination with an appropriate material for a mass spectrometric application are addressed; special attention is paid to chemical compatibility, ease of production, and cost. In this review, we critically discuss these developments and assess their impact on mass spectrometry.

Reinventing (Bio)chemical Analysis with Paper.

This paper focuses on one of the most commonly encountered materials in our society, namely paper. Paper is an inherently complex material, yet its use provides for chemical analysis approaches that are elegant in their simplicity of execution. In the first half of the previous century, paper in scientific research was used mainly for filtration and chromatographic separation. While its use decreased with the rise of modern elution chromatography, paper remains a versatile substrate for low-cost analytical tests. Recently, we have seen renewed interest to work with paper in (bio)analytical science, a result of the growing demand for inexpensive, portable analysis. Dried blood spotting, paper microfluidics, and paper spray ionization are areas in which paper is (re)establishing itself as an important material. These research areas all exploit several properties of paper, including stable sample storage, passive fluid movement and manipulation, chromatographic separation/extraction, modifiable surface and/or volume, easily altered shape, easy transport, and low cost. We propose that the real, and to date underexploited, potential of paper lies in utilizing its combined characteristics to add new dimensions to paper-based (bio)chemical analysis, expanding its applicability. This article provides the reader with a short historical perspective on the scientific use of paper and the developments that led to the establishment of the aforementioned research areas. We review important characteristics of paper and place them in a scientific context in this descriptive, yet critical, assessment of the achieved and the achievable in paper-based analysis. The ultimate goal is the exploration of integrative approaches at the interface between the different fields in which paper is or can be used.

3D-Printed Paper Spray Ionization Cartridge with Integrated Desolvation Feature and Ion Optics.

In this work we present the application of 3D-printing for the miniaturization and functionalization of an ion source for (portable) mass spectrometry (MS). Two versions of a 3D-printed cartridge for paper spray ionization (PSI) are demonstrated, assessed, and compared. We first focus on the use of 3D-printing to enable the integration of an embedded electrostatic lens and a manifold for internal sheath gas distribution and delivery. Cartridges with and without a sheath gas manifold and an electrostatic lens are compared with respect to analytical performance and operational flexibility. The sensitivity and limit of detection are improved in the cartridge with an electrostatic lens and sheath gas manifold compared to the cartridge without (15% and over 6.5× smaller, respectively). The use of these focusing elements also improved the average spray stability. Furthermore, the range of potentials required for PSI was lower, and the distance to the MS orifice over which spray could be obtained was larger. Importantly, both setups allowed quantification of a model drug in the ng/mL range with single-stage MS, after correction for spray instability. Finally, we believe that this work is an example of the impact that 3D-printing will have on the future of analytical device fabrication, miniaturization, and functionalization.

Solvent-dependent on/off valving using selectively permeable barriers in paper microfluidics.

We report on a new way to control solvent flows in paper microfluidic devices, based on the local patterning of paper with alkyl ketene dimer (AKD) to form barriers with selective permeability for different solvents. Production of the devices is a two-step process. In the first step, AKD-treated paper (hydrophobic) is exposed to oxygen plasma for re-hydrophilization. 3D-printed masks are employed to shield certain areas of this paper to preserve well-defined hydrophobic patterns. In the second step, concentrated AKD in hexane is selectively deposited onto already hydrophobic regions of the paper to locally increase the degree of hydrophobicity. Hydrophilic areas formed in the previous oxygen plasma step are protected from AKD by wetting them with water first to prevent the AKD hexane solution from entering them (hydrophilic exclusion). Characterization of the patterns after both steps shows that reproducible patterns are obtained with linear dependence on the dimensions of the 3D-printed masks. This two-step methodology leads to differential hydrophobicity on the paper: (i) hydrophilic regions, (ii) low-load AKD gates, and (iii) high-load AKD walls. The gates are impermeable to water, yet can be penetrated by most alcohol/water mixtures; the walls cannot. This concept for solvent-dependent on/off valving is demonstrated in two applications. In the first example, a device was developed for multi-step chemical reactions. Different compounds can be spotted separately (closed gates). Upon elution with an alcohol/water mixture, the gates become permeable and the contents are combined. In the second example, volume-defined sampling is introduced. Aqueous sample is allowed to wick into a device and fill a sample chamber. The contents of this sample chamber are eluted perpendicularly with an alcohol/water mixture through a selectively permeable gate. This system was tested with dye solution, and a linear dependence of magnitude of the signal on the sample chamber size was obtained.