A rapid method for the quantitation of sixteen neutral and acidic monosaccharides, from both animal and plant sources was developed using ultra-high performance liquid chromatography triple quadrupole mass spectrometry (UHPLC/QqQ-MS) in dynamic multiple reaction monitoring (dMRM) mode. Monosaccharides including three pentoses (ribose, xylose, arabinose), two deoxyhexoses (rhamnose, fucose), five hexoses (fructose, mannose, allose, glucose, galactose), two hexuronic acids (glucuronic acid, galacturonic acid), and two N-acetyl-hexosamines (GlcNAc, GalNAc), were derivatized with 1-phenyl-3-methyl-5-pyrazolone (PMP), while underivatized sialic acids, N-acetylneuraminic acid (Neu5Ac) and N-glycolylneuraminic acid (Neu5Gc), were simultaneously analyzed with a 10-minute run. With the optimized UHPLC conditions, baseline separations of the isomers were achieved. The sensitivity and calibration ranges of this method were determined. The limits of detection were between femtomoles and attomoles with linear ranges spanning four to six orders of magnitude and CVs ≤ 7.2%. Spiking experiments performed on a pooled fecal sample demonstrated the high accuracy of this method even when applied to samples with complicated matrices. The validated method was applied to fecal samples from an infant transitioning from breast milk to weaning foods. Major milk monosaccharides including galactose, fucose, glucose, GlcNAc, and Neu5Ac were found to be the most abundant components in the feces of milk-fed infants. PMP-derivatives of other monosaccharides including apiose, lyxose, altrose, talose, gulose, glucosamine, galactosamine, mannosamine, and N-acetylmannosamine (ManNAc) were also tested and could be added to the quantitation method depending on the need. The speed and sensitivity of the method makes it readily adaptable to rapid throughput analysis of monosaccharides in biological samples.

Seeking efficient visible-light-driven photocatalysts for water splitting to produce H 2 has attracted much attention. Chemical doping is an effective strategy to enhance photocatalytic performance. Herein, we reported phosphorus-doped covalent triazine-based frameworks (CTFs) for photocatalytic H 2 evolution. Phosphorus-doped CTFs were fabricated by a facile thermal treatment using easily available red phosphorus as the external phosphorus species. The introduction of phosphorus atoms into the frameworks modified the optical and electronic property of CTFs, thus promoting the generation, separation, and migration of photoinduced electron−hole pairs. Consequently, the photocatalytic H 2 -production efficiency of phosphorus-doped CTFs was greatly improved, which was 4.5, 3.9, and 1.8 times as high as that of undoped CTFs and phosphorusdoped g-C 3 N 4 calcined from melamine and urea, respectively.

Photocatalytic reduction of carbon dioxide to hydrocarbon fuel provides a sustainable strategy for addressing the increasing energy crisis as well as alleviating the greenhouse effect. Yet, seeking effective, affordable, and metal-free photocatalysts is still a challenging issue. Herein, a novel nitrogen selfdoped covalent triazine-based framework (NCTF-1) was prepared via a simple hydrothermal process for photocatalytic CO 2 reduction to CH 4 using visible light. NCTF-1 exhibited a CH 4 evolution rate of 11.48 μmol g −1 h −1 , corresponding to ninefold enhancement, compared with bare covalent triazine-based frameworks (CTF-1). The photocatalytic enhancement mechanism was probed by a variety of instrumental measurements. Results showed that the modification of nitrogen atoms in NCTF-1 could extend the responsive range of the visible-light spectrum, promote CO 2 capture, and thus greatly elevate the photocatalytic CO 2 reduction activity. Notably, NCTF-1 displayed a satisfactory selectivity for CO 2 conversion with CH 4 accounting for over 85% of the reduction products. This study offers a promising avenue for achieving robust CO 2 -to-CH 4 conversion and provides insight into the impact of nitrogen self-doping on covalent triazine-based frameworks.