A total of 15 representative organophosphorus pesticides (OPPs), a class of water pollutants causing serious global concerns, have been sensitively quantified by internal extractive electrospray ionization mass spectrometry (iEESI-MS) after enrichment with Fe3O4–ZrO2 innovatively synthesized in our lab by a one step coprecipitation method. For the premium enrichment, the amounts of Fe3O4–ZrO2, pH value, adsorption time, type and volume of desorption solvent, and shaking time of desorption were systematically optimized. Under optimized conditions, the proposed method provided low limits of detection (LODs) of 0.14–16.39 ng L–1 with relative standard deviations (RSDs) of less than 8.7%. A wide linear response range of about 4 orders of magnitude was achieved with linear coefficients (R 2) of 0.9921–0.9999 for all the analytes tested. The present method also provided good recoveries (85.4–105.9%) with acceptable precision (RSDs < 7.2%) in spiked environmental water samples. Furthermore, multiple analytes including dimethoate, omethoate, etc. were simultaneously detected in a single sample run, which was accomplished within 1 min, resulting in significantly improved analytical throughput for quantitative analysis of bulk amounts of samples. The experimental results demonstrated that Fe3O4–ZrO2-iEESI-MS provided advantages, including high sensitivity, high speed, and reasonable selectivity for the detection of OPPs, showing potential applications in environmental water sample analysis and environmental science.

Fe2TiO5 is recognized as a novel and promising photoanode material for solar water splitting. Here, nanostructured Fe2TiO5 was fabricated on a fluorine-doped tin oxide substrate by an electrospray deposition technique. We utilized surface Al3+ treatment and FeOOH modification to improve performance of the Fe2TiO5 photoanode. After this two-step enhancement, the photocurrent density of the final Fe2TiO5 photoanode is 0.52 mA cm–2 at 1.23 VRHE which is 2.8 times that of the pristine one, and the onset potential is 200 mV lower than before. The enhanced performance can be attributed to a synergetic effect of surface Al3+ treatment and FeOOH modification, since the surface Al3+ treatment accelerates charge transport while the FeOOH layer improves catalytic activity. This strategy of surface modification provides an effective pathway for rational designing of original photoanodes with high practical performance.

Water radical cations, (H2O)n+•, have attracted considerable attention owing to their potential practical applications in analytical chemistry, structural chemistry, radiotherapy, and radiochemistry. Recently, atmospheric pressure chemical ionization has emerged as a versatile method for direct mass spectrometric analysis. Usually, H3O+ is the major proton donor during ionization and only the pseudo molecular ion peaks, instead of molecular ions are detected. In this work, (H2O)2+• ions with high oxidizability and reactivity were generated using hydrothermally grown TiO2 nanoneedle arrays in combination with a linear ion trap mass spectrometer under low operating voltage and applied to the direct mass spectrometric analysis of a mixture of volatile aromatic hydrocarbons. (H2O)2+• ions were generated with a high absolute ion current of up to 1.07 × 105 counts/s at atmospheric pressure. Using the generated (H2O)2+• as the primary ion permitted the tandem mass spectrometric analysis of a mixed vapor sample of aromatic hydrocarbons.