Chiral analysis is critical to many research fields due to different biological functions of enantiomers in living systems. Although the use of ion mobility spectrometry (IMS) has become an alternative technology in the area of chiral measurements, there is still a lack of a general chiral selector for IMS-based chiral recognition, especially for small chiral molecules. Here, a new method using oligosaccharides as the chiral selector has been developed to discriminate chiral amino acids (AAs) by trapped ion mobility spectrometry-mass spectrometry (TIMS-MS). We analyzed 21 chiral amino acids, including small molecules (e.g., alanine and cysteine). Our data showed that the use of nonreducing tetrasaccharides was effective for the separation of chiral AAs, which differentiated 21 chiral AAs without using metal ions. By further incorporating a copper ion, the separation resolution could be improved to 1.64 on average, which accounts for an additional 52% improvement on top of the already achieved separation in metal-free analysis. These results indicate that the use of tetrasaccharides is an effective strategy for the separation of AA enantiomers by TIMS. The method developed in this study may open up a new strategy for effective IMS-based chiral analysis.

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Rationale Ion mobility spectrometry (IMS) is a powerful analytical tool that has been widely applied in many fields. However, the limited structural resolution of IMS results in peak overlapping in the analysis of samples with similar structures. We propose a novel method, improved particle swarm optimization (IPSO), for the separation of IMS overlapping peaks. Methods This method, which prevents local optimization, is used to identify the peak model coefficients of IMS. Moreover, we use the half‐peak width characteristics of IMS to determine the particle position range, which eliminates impossible combinations of single peaks and reduces the difficulty of identification of coefficients. Results During a comparison in performance between IPSO and the genetic algorithm (GA), the results show that the maximum separation error of IPSO is only 1.45%, while the error of the GA is up to 17.43%. Moreover, the time consumed by IPSO is 95% less than that of the GA, and IPSO has a greater robustness under the same separation error conditions. Conclusions The method proposed provides accurate analytical results in separating overlapping IMS peaks even in cases of severe overlaps, which greatly enhances the structural resolution of IMS.

CH3NH3PbI3 (MAPbI3)-based perovskite solar cells (PSCs) with special hole and electron transport layers (HTL and ETL) were prepared to study their light-induced degradation. Obvious degradation was observed under initial light exposure not only at the device level but also at the film morphology and electronic structure level. Device performance parameters, such as short-circuit current (JSC), power conversion efficiency, fill factor, and hysteresis effect, were aggravated with an initial light exposure of less than ∼8 h at 1 sun intensity. Meanwhile, the deteriorated crystallinity and electronic structure of the MAPbI3 film were also detected with x-ray diffraction, ultraviolet photoelectron spectroscopy, and UV-Visible absorption spectroscopy. The observed degradation is rationally related to the light-induced decomposition of MAPbI3. However, the degradation can be partly recovered with the following light exposure resulting in self-healing of the devices and MAPbI3 films. The self-healing behavior should be ascribed to the conversion of decomposition products back to MAPbI3, because the intermediates are wrapped tightly in the photoactive layer by the compact coverlayers of HTLs and ETLs and some reversible reactions occur consequently. The mechanism of self-healing is discussed by introducing the trapped states derived from ion migration. The PSCs prepared here imply a good optical stability and thus a good performance facilitated by tight wrapping of the active MAPbI3.

The combination of chiral derivatization and ion mobility-mass spectrometry provides the first insights into the separation of 19 pairs of chiral proteinogenic d/l-amino acids in a single run and detection of chiral amino acids in complex samples.

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3-Pyridinylboronate, a zwitterionic boronic acid, displayed effective in-situ ESI for reversible covalent tagging of saccharides in both cation and anion modes. The ion mobilities of thus generated ions were examined...

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