Scene effects on disgusted facial expression detection in individuals with social anxiety: The role of emotional intensity.

Individuals exhibiting high social anxiety (HSA) typically encounter challenges in identifying threatening stimuli with varying levels of intensity in different social scenes, ultimately affecting their social interactions. However, it is not well understood how social scenes, emotional intensity, and interaction influence the recognition of threat stimuli among HSA individuals (HSAs). To address this issue, a face recognition task was administered to 20 HSA participants and 22 individuals exhibiting low social anxiety (LSA) in this study. Results indicated that during the social scene presentation stage, HSAs produced larger P2 amplitude than LSA individuals (LSAs) no matter the valence of the scenes. During the face recognition stage, HSAs had smaller N170 amplitude than LSAs and exhibited lower recognition time for 2 % disgusted faces compared to LSAs. Furthermore, the consistency between scenes and faces led to faster recognition of disgusted faces in HSAs, but not in LSAs. Consequently, our findings suggested that HSAs exhibited unique cognitive processing patterns in social scenes, manifested by increased attention to scenes and decreased attention to faces. In addition, the emotional congruence between the scene and the faces could facilitate the recognition of faces by HSAs.

Development of an LC-MS Method for 4-Fluoroaniline Determination in Ezetimibe.

A rapid and sensitive high-performance liquid chromatography-mass spectrometry method was developed and validated to determine 4-fluoroaniline concentration in ezetimibe. Chromatographic separation was achieved on a Phenomenex Gemini-NX C18 column (150 × 4.6 mm, 3 µm) maintained at 30°C. The liquid chromatography system was operated in gradient mode with an injection volume of 20 µL at a flow rate of 1 mL/min. Mobile phase A was water and mobile phase B consisted of acetonitrile with 0.05% acetic acid. The detection was performed using a single quadrupole mass spectrometer in single ion monitoring mode by using positive ionization. An m/z value of 112 was selected for monitoring 4-fluoroaniline. The method showed good linearity over the concentration range of 0.94-30.26 ng/mL. The limit of quantification and limit of detection were 0.19 and 0.94 ng/mL, respectively. The precision relative standard deviations were less than 8.7% (n = 12), and the accuracy values were within 92-99%. A standard solution of 4-fluoroaniline was stable for at least 24 h at 25°C. Small changes in the organic phase acidity of the mobile phase, flow rate, column temperature, and the instrument parameters had no significant effect on the results for 4-fluoroaniline.

Fast and Simple Determination of 3-Aminopiperidine without Derivatization Using High Performance Liquid Chromatography-Charged Aerosol Detector with an Ion-Exchange/Reversed-Phase Mixed-mode Column.

A sensitive non-derivatization method for the determination of the highly polar compound 3-aminopiperidine was developed using a mixed-mode column combined with a charged aerosol detector (CAD). Chromatographic conditions, including the type of detector, separation mode, and mobile phase composition, were optimized to achieve high sensitivity towards and sufficient retention of 3-aminopiperidine. Compared to the precolumn derivatization UV method, the current method showed higher recovery and greater simplicify. High sensitivity (LOQ <2.73 µg mL-1) and good precision (RSD of peak area <2%) were also observed in the current method. Furthermore, the parameters such as buffer solution and column bleed that affected the sensitivity of the CAD were investigated. Finally, the current method was applied for the determination of 3-aminopiperidine in linagliptin samples. This is a new non-derivative for the determination of 3-aminopiperidine, and constitutes a novel application of the CAD for the quantitative analysis of highly polar basic compounds.

A Sensitive Precolumn Derivatization Method for Determination of Piperazine in Vortioxetine Hydrobromide Using a C8 Column and High-Performance Liquid Chromatography-Mass Spectrometry.

A rapid and sensitive high-performance liquid chromatography-mass spectrometry method was established to determine the trace residues of piperazine in vortioxetine hydrobromide. The presence of piperazine was determined by precolumn derivatization with dansyl chloride. Chromatographic separation was performed on a Waters SunFire C8 column (150 × 4.6 mm, 3.5 µm) in gradient elution mode, using formic acid and acetonitrile as mobile phase. Detection was performed in a single quadrupole mass spectrometer in single ion monitoring mode using positive ionization. An m/z value of 553 was selected for monitoring disubstituted piperazine by DNS-Cl. Linearity, accuracy, and precision were found to be acceptable over the piperazine concentration range of 0.3525 - 2.35 ng mL-1. The limit of detection and limit of quantification of piperazine were 0.1175 and 0.3525 ng mL-1, respectively, which complied with the requirements of qualitative and quantitative analyses. The method was deemed sensitive and efficient.