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Measuring the concentration of PAHs in the freely dissolved phase is crucial for assessing ecological impacts in the marine environment. However, various environmental conditions make short-term monitoring challenging. This study used an optimized High Speed Rotation-Type Passive Sampling Device (HSR-PSD) equipped with linear low-density polyethylene (LLDPE) to conduct the first nationwide monitoring of freely dissolved PAHs in Korean coastal waters. The HSR-PSD enabled faster short-term monitoring by measuring C free of PAHs within 12 h and was less affected by environmental conditions compared to conventional PSDs. Σ 15 PAH concentrations ranged from 2.8 to 9.4 ng/L, with significantly higher levels on the western coast. Anthropogenic activities and oceanic conditions affected C free distribution in coastal areas. Based on C free , the estimated PAH levels in bivalves and fish were aligned with reported tissue concentrations, exhibiting low ecological risk to aquatic organisms. Therefore, the HSR-PSD with LLDPE is a suitable tool for nationwide short-term monitoring. • The freely dissolved PAHs were first monitored nationwide in Korean coastal waters. • Automatic passive sampler with LLDPE is an suitable tool for short-term monitoring. • Anthropogenic activities and oceanic conditions together affect C free distribution. • Estimated PAHs level in bivalves and fish using C free align with tissue concentration. [ABSTRACT FROM AUTHOR]

Polycyclic aromatic hydrocarbons (PAHs) are characterized with high K OW values, which lead to their recalcitrant nature, bioaccumulation, and biotoxicity, adversely affects the environment. Passive samplers (PS) have proven effective in measuring bioavailable PAH concentrations for toxicity assessments. In this study, we used low-density polyethylene (LDPE) to measure freely dissolved PAH concentrations (C free) in Kentucky Lake (KL) and Ohio River (OH), USA. PAHs toxicity potential in sediment was assessed using equilibrium partitioning sediment benchmarks toxic units (ESBTUs) and the interstitial water toxic units (IWTUs) that were derived from OC-normalized concentration (C OC) and C free , respectively. The C free in April and June were 127 and 97 times higher in OH than in KL, respectively. Moreover, ESBTUs were higher in both the KL and OH compared to the IWTUs, suggesting that ESBTUs overestimate the toxicity potential to organisms. These results indicate that PS provides a reliable method for assessing the toxicity potential in sediments. [Display omitted] • The freely dissolved PAHs in Ohio River were higher than those in Kentucky Lake. • PAHs more strongly adsorb to sediments in the Ohio River than in Kentucky Lake. • The conventional method overestimated the toxicity potential by a factor of 33. • PAHs in sediments from both regions did not exhibit toxicity to organisms. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Fluorometric analysis of BH 4 – was studied using anthracene- and pyrenecarboxaldehyde. • Borohydride signaling was due to the reduction of arylaldehydes to the arylmethanols. • Probes exhibited pronounced ratiometric fluorescence signaling behavior toward BH 4 –. • Convenient determination of borohydride was possible using probe embedded-μPAD. Abstract Fluorometric analysis of borohydride (BH 4 –) species by the reduction of arylaldehydes to the corresponding arylmethanols was investigated. 9-Anthracenecarboxaldehyde (9-AA) exhibited pronounced ratiometric fluorescence signaling behavior toward borohydride in alkaline aqueous media. The borohydride-selective signaling of 9-AA was unaffected by the presence of commonly encountered metal ions and anions. 1-Pyrenecarboxaldehyde (1-PA) also showed comparable borohydride signaling behavior. The detection limit was found to be 7.4 μM (0.11 ppm) for 9-AA and 15.7 μM (0.23 ppm) for 1-PA. The utility of the probe with μPAD as a convenient tool for the determination of borohydrides was demonstrated. [ABSTRACT FROM AUTHOR]

Malononitrile is a key starting material used in synthetic organic, medical, and industrial chemistry, but it is also a notorious cyanogenic toxicant. However, selective and sensitive analytical methods for this key chemical are rare. In this research, a novel reaction-based colorimetric signaling probe for the selective analysis of malononitrile via the S N Ar-type nucleophilic substitution reaction of an NBD-based phenyl selenoether was investigated. The probe exhibited a pronounced colorimetric response, with a color change from yellow to violet due to its CH-acidity. The interference of sulfide ions and several transition metal ions was effectively circumvented with the use of copper foil as a sulfide scavenger and EDTA as a masking agent for the metal ions. The detection limit of the probe for malononitrile was found to be 264 nM. It was also demonstrated that this convenient colorimetric analysis of malononitrile in chemical and industrial applications using the probe can be conducted with an office scanner. Image 1 • Colorimetric malononitrile probe based on NBD-phenyl selenoether was investigated. • The probe manifested a color change from yellow to violet via an S N Ar-type reaction. • Interferences from sulfide and transition metals were suppressed by Cu foil and EDTA. • Colorimetric analysis of malononitrile was easily conducted with an office scanner. [ABSTRACT FROM AUTHOR]

We report three DTBDT-based small molecules with various end groups and the effects of end-group tuning on their photovoltaic properties. We designed and synthesized DTBDT-Rho, DTBDT-EC, and DTBDT-CN, which have 3-ethylrhodanine, dicyanovinyl, and ethyl cyanoacetate, respectively, as end groups. DTBDT-EC and DTBDT-CN have much deeper LUMO and HOMO energy levels than DTBDT-Rho due to the stronger electron withdrawal of their end groups. As expected, the three DTBDT-based small molecules exhibit disparate bulk heterojunction blend morphologies and photovoltaic properties. DTBDT-Rho exhibits superior miscibility with PC 71 BM in blend films as well as crystalline structure within DTBDT-Rho domains, which result in solar cell devices with outstanding photovoltaic performances, namely PCEs above 7%. In contrast, DTBDT-CN gives rise to devices with poor performance of PCEs near 2%. It exhibits excessive molecular aggregation with less favorable molecular packing. Our study of end group tuning and morphological analysis provides valuable guidelines for the design of new small molecules and insight into their photovoltaic performances. [ABSTRACT FROM AUTHOR]

A new fluorescent probe for the selective detection of industrially important peracetic acid (PAA) was developed via oxidative cleavage of the phenylselenyl ether derivative of the 4-hydroxynaphthalimide. The probe showed no noticeable changes towards common oxidants and environmentally relevant metal ions and anions. Furthermore, PAA signaling was not influenced by the presence of background ionic species, except for certain redox-active species. Practical application of the probe to the determination of PAA in tap water and atmosphere was successfully executed using a smartphone as a stand-alone signal capturing and processing device. [ABSTRACT FROM AUTHOR]

We report on the structural and electrical properties of phosphorous-doped ZnS x O1− x films grown by radiofrequency magnetron sputtering. The band gap decreased with increasing sulfur composition in phosphorus-doped ZnS x O1− x films because of the band bowing effect. The conductivity of phosphorus-doped ZnS x O1− x films changed from n-type to p-type, and the p-type doping efficiency of phosphorus in ZnO was increased as the sulfur content in phosphorus-doped ZnS x O1− x was increased. [ABSTRACT FROM AUTHOR]