Rapid screening of riot control agents using DART-TD-HRMS.

PURPOSE: Riot Control Agents (RCAs) are chemicals used in law enforcement for non-lethal riot control and use in conflicts between states that violates the Chemical Weapons Convention. OPCW's Scientific Advisory Board has identified sixteen potential RCAs including capsaicinoids, CS, and CR. RCAs may be misused for criminal purposes, so methods for detecting such misuse are needed. This study therefore evaluates the feasibility of a rapid, high throughput screening method of RCAs on surfaces (particularly clothing surfaces) by Direct Analysis in Real Time with a thermal desorption unit coupled to high-resolution mass spectrometry (DART-TD-HRMS). METHODS: A broadly applicable method for detecting potential RCAs was developed and tested on cotton fabric samples sprayed with self-defence sprays from an in-house reference stock. The feasibility of detecting RCAs by direct analysis of surface wipe samples placed in the DART source was also investigated. RESULTS: The method detected all sixteen RCAs and contaminated clothing were successfully screened for active agents in a reference collection of self-defence sprays. A pilot study also showed that RCAs can be detected by holding a sample directly in front of the DART source. CONCLUSION: DART-TD-HRMS enables rapid and simple screening of RCAs on fabric samples enabling a high sample throughput.

Weak Lips? A Possible Merger of /i:/ and /y:/ in Gothenburg.

BACKGROUND/AIMS: This study investigates a possible merger in the early stages between /i:/ and /y:/ among young speakers in Gothenburg, Sweden. METHODS: (1) A large-scale online perception experiment testing listeners' abilities to identify the two vowels and (2) acoustic analysis of 705 vowels from 19 speakers. RESULTS: The perception study shows that listeners classify the horizontally centralized /y:/ as /i:/, both in isolated vowel items and in items containing the full word. This indicates that /y:/ is moving into the perceptual space of /i:/. Listeners also classify the unmerged /y:/ as /i:/ when listening to [y:] in isolation, indicating that lip rounding is a perceptually weak feature, for this centralized vowel, in this variety. The acoustic analysis shows that /i:/ tends to be produced as [ɨ:], and that there is no acoustic difference between /i:/ and /y:/ in measurements correlated with the first two formants, i.e. lip rounding is the most important distinctive feature. CONCLUSION: Results point in the direction of an incipient vowel merger, following a merger-by-approximation model. These results indicate a lack of perceptual strength of an articulatory feature in the disappearing phoneme, namely lip rounding, and the consequent perceptual similarities between the horizontally centralized [ɨ:] and /y:/.

Process water properties from hydrothermal carbonization of chemical sludge from a pulp and board mill.

Hydrothermal carbonization (HTC) can be used to break down sludge structure and generate carbonaceous hydrochar suitable for solid fuel or value-added material applications. The separation of char and the reaction medium however generates a filtrate, which needs to treated before potential discharge. Thus, this work determined filtrate properties based on HTC temperature and sludge moisture content and estimated the discharge emissions and the potential increase in analyte loads to an industrial wastewater treatment plant based on derived regression models. Direct discharge of HTC filtrate would significantly increase effluent emissions at the mill, indicating the filtrate treatment is crucial for the future implementation of HTC at pulp and paper mills. Recycling the HTC filtrate to the wastewater plant would lead to only a nominal increase in effluent flow, but would increase the suspended solids, BOD, COD and total nitrogen loads by 0.1-0.8%, 3.8-5.3%, 2.7-3.1% and 42-67%, respectively, depending on HTC temperature.