Open Access

The report describes preparation, analysis and certification of the certified copper reference material BAM-M380, which is intended for establishing and checking the calibration of optical emission spectrometers for the analysis of samples of similar matrix composition.

We present a high-throughput approach for synthesizing palladium nanoparticles (PdNPs), which are widely used as catalysts in industrial processes, employing an aqueous reaction medium and a commercial reaction platform that enables parallel reactions under identical conditions. The optimal synthesis conditions, including reaction temperature and the concentrations of Pd, thiol ligands (3-mercaptopropionic acid (MPA) and L-cysteine (Cys)), and reducing agent, were established using a Doehlert experimental design. The purified thiol-capped PdNPs were characterized by transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), dynamic light scattering (DLS), and nanoparticle tracking analysis (NTA), confirming the formation of irregularly shaped PdNP-MPA and PdNP-Cys with polydispersity indices up to 0.270. Single particle-inductively coupled plasma-mass spectrometry (sp-ICP-MS) enabled determination of particle size and size distribution, demonstrating its suitability for characterizing polydisperse nanoparticles with irregular shapes and yielding results consistent with those obtained by TEM and NTA. Bulk ICP-MS was employed to determine the surface density of thiol ligands from the sulfur-to-palladium ratio. Overall, this study demonstrates the potential of multivariate experimental design for PdNP synthesis and the value of complementary analytical techniques for comprehensive nanoparticle characterization.

In ion-based analytical techniques the possibility to spatia ly manipulate ions is fundamenta ly important. Most ion optics rely on magnetic or electric fields and are most effective under low pressure. Acoustic ion manipulation (AIM) is a recently discovered phenomenon that relies on the unique interactions between gas-phase ions and acoustic waves. Through AIM, ion trajectories are altered based on physical properties by transient pressure gradients. These manipulations are performed at ambient conditions. Methods The influence of strong dynamic and stationary acoustic fields on neutral and charged gas streams was studied by exposing them to either a standing acoustic wave, traveling waves, or directional multi-speaker arrays. Most speakers were driven at 40 kHz with 20 Vp-p. Additionaly, Langevin-type ultrasonic transducers and transducers with frequencies of up to 315 kHz and 100-150 Vp-p were employed. Ions were produced with either an in-house built electrospray ionization (ESI) source or a plasma-based source, forming laminar ion streams. Al experiments were carried out using an Orbitrap mass spectrometer. The visualization of acoustic fields was achieved by defocusing shadowgraphy. Main results Detected ion signal from outlet of a plasma source into the MS inlet increased two to three times upon passing through the node of a standing wave inside an acoustic resonator. Conversely, an antinode in the path of the ion trajectory effectively blocked the ion signal with a gating efficiency of 99.9%. Furthermore, ion streams can be separated according to ion-specific properties (e.g., m/z, colisional cross section, or charge state) by the selective efficacy of acoustic-ion interactions. When exposed to traveling acoustic waves, ions exhibited a trend to fo low the transient pressure gradients, thereby getting deflected from their original track. The directional transducer array showed possibilities to confine ion clouds spatia ly upon this redirection. Fina ly, altering the acoustic frequency helps to achieve more flexibility in future designs and to gain a better understanding of the underlying physics.

The functionalization of a hexa-peri-benzocoronene–fluoranthene hybrid with a K-type bay region is investigated. Bromination proceeds regioselectively at two peripheral positions, which contradicts the electronic and structural predictions suggesting that substitution at the K-type bay region should be favored. Computational studies reveal that the transition state and intermediate energies for all substitution positions are comparable, though no substitution in the bay region is observed. To rationalize this unexpected regioselectivity, a model is proposed based on dynamic helical inversion, which prevents the corresponding Wheland intermediates from being stabilized. Subsequent conversion of the brominated compounds to nitrile derivatives affords compounds with photoluminescence quantum yields of up to 76% in solution. Organic light-emitting diodes with luminance values of up to 6,500 cd·m–2 are realized due to the effective energy level alignment by a hole-transport and electron-blocking layer, which was not possible with the related nonfunctionalized derivative.

Per- and polyfluoroalkyl substances (PFAS) are synthetic chemicals that have been manufactured since the 1940s. Key compounds belong to perfluoroalkyl carboxylic acids (PFCA), perfluoroalkyl sulfonic acids (PFSA) and fluorotelomer sulfonic acids (FTSA). However, the highly stable PFAS – often referred to as “forever chemicals” – are a growing global concern due to their persistence in the environment and their potential to pose risks to public health and ecosystems. Within the broad range of applications in consumer products, textiles and other outdoor products are a major source of PFAS exposure due to their water-repellent impregnations. Determination of PFAS in textiles is of increasing importance, because textiles are essential for shifting towards a circular economy and achieving climate neutrality. Although there are maximum levels and restrictions for certain PFAS key compounds under the Stockholm Convention on Persistent Organic Pollutants (POP) and the REACH Regulation, there are currently no certified reference materials (CRMs) available for PFAS in textiles. The aim of our project was therefore to address this issue by developing the first CRM for PFAS in textiles that is fully compliant to ISO 17034 and ISO 33405. The recently certified CRM BAM-B003 is useful for laboratories monitoring PFAS maximum levels, e.g. according to Oeko-Tex® Standard 100. This poster presents an overview of the entire process including preparation and characterization of the CRM. In-house certification was conducted at BAM based on the LC–MS/MS standard method for PFAS in textiles EN 17681–1. The certified mass fractions of 18 PFAS range widely, with a prevalence of PFOA (69 μg/kg), PFOS (41 μg/kg) and PFHxA (35 μg/kg) exceeding legal limits. BAM-B003 contributes to improving the chemical safety of textiles and strengthening the circular economy.