@article {JING2020120378, title = {Sorbent and solvent co-enhanced direct analysis in real time-mass spectrometry for high-throughput determination of trace pollutants in water}, journal = {Talanta}, volume = {208}, year = {2020}, pages = {120378}, abstract = {

A sorbent and solvent co-enhanced direct analysis in real-time mass spectrometry (SSE-DART-MS) method was developed for high-throughput determination of trace pollutants in water. The use of sorbent for preconcentration and solvents for assisting desorption and ionization synergistically enhanced the signals from the trace pollutants detected by DART-MS. Phthalic acid esters (PAEs) were used as model analytes to validate the SSE-DART-MS method. Graphitic carbon nitride (g\–C3N4)\–based materials with two morphologies and six organic solvents were used to systematically evaluate the enhancement effect by the sorbent and solvent. A better analytical performance was achieved with the two-dimensional (2D) g-C3N4, compared to three-dimensional (3D) g-C3N4/C, indicating that the morphologies of sorbents played a key role in SSE-DART-MS analysis. The MS signals of all the analytes were increased by 10\–100 times for the two materials in the presence of the selected solvents. With the SSE-DART-MS method, concentration limits of detection for water samples in the range 0.07\–0.94 ng L\−1, and recovery in the range 82.8\–119\% using g-C3N4, were obtained for the PAEs. This work not only provides a reliable method for the coupling of solid phase extraction technique with DART-MS, but also presents valuable information for conducting other DART-MS analyses.

}, keywords = {desorption, direct analysis in real time mass spectrometry, Graphitic carbon nitride, IONIZATION, Phthalic acid esters, Solid phase extraction}, issn = {0039-9140}, doi = {https://doi.org/10.1016/j.talanta.2019.120378}, url = {http://www.sciencedirect.com/science/article/pii/S0039914019310112}, author = {Wenqiang Jing and Yanying Zhou and Jiaqin Wang and Yuanfeng Zhu and Youqi Lv and Wentao Bi and Chen, David D. Y.} } @article {JIANG2019, title = {Simultaneous determination of multiple components in cigarettes by mechanochemical extraction and direct analysis in real time mass spectrometry in minutes}, journal = {Analytica Chimica Acta}, volume = {1057}, year = {2019}, month = {05/2019}, pages = {70-79}, abstract = {

A simple, rapid and high throughput analytical approach with combination of mechanochemical extraction (MCE) and direct analysis in real time mass spectrometry (DART-MS) analysis was developed for the simultaneous determination of multiple chemical components in cigarette fillers. Different kinds of substances including nicotine, cigarette alkaloids, carbohydrates, organic acids, humectants and other additives were successfully extracted using MCE and detected by high resolution DART-MS. Six solvents of various polarities were compared during MCE process and significant differences were observed. Different brands of cigarettes as well as standard research cigarette exhibited distinctive chemical features and DART-MS fingerprints. Principle component analysis showed clear differentiation among different cigarettes extracted with the same solvent and different solvent extracts of the same type of cigarette. The putative chemical formulas were proposed based on accurate m/z values with \<10 ppm mass errors. The relative contents of nicotine and other identified substances were compared and significant differences were observed among cigarettes of different locations. The whole procedure of MCE combined with DART-MS only takes minutes from raw cigarette fillers to obtaining the semi-quantitative results. The operation is simple and high throughput, providing an efficient method to analyze cigarette composition, and to establish a methodology to acquire the rapid cigarette fingerprints for quality control.

}, keywords = {Cigarette filler, direct analysis in real time mass spectrometry, Mechanochemical extraction, Principle component analysis}, issn = {0003-2670}, doi = {https://doi.org/10.1016/j.aca.2019.01.024}, url = {http://www.sciencedirect.com/science/article/pii/S0003267019300935}, author = {Qing Jiang and Diya Dai and Hongli Li and David D.Y. Chen} } @article {WANG20198, title = {Solvent-free high-throughput analysis of herbicides in environmental water}, journal = {Analytica Chimica Acta}, volume = {1071}, year = {2019}, month = {04/2019}, pages = {8 - 16}, abstract = {

A high throughput, and eco-friendly method based on solid-phase microextraction (SPME) combined with direct analysis in real time mass spectrometry (DART-MS) was established for the determination of trace pollutants in water. A laboratory-made SPME device coated with a metal organic framework (MIL-100 (M)) was fabricated for the on-site enrichment of triazine herbicides in environmental water, and the device was directly subjected to DART ionization (\<20 s) for high resolution MS. The interactions between the target analytes and sorbents were investigated to improve the SPME device targeting specific pollutants, as well as to improve the desorption and ionization processes with DART-MS. Other factors were also systematically studied to obtain the optimal conditions, including pH, salinity, extraction temperature, pressure at the Vapur\® interface, linear rail moving speed, gas temperature, extraction time, and sample volume. The limit of detection of target compounds were 5.0\–50.0 ng L\−1 and the recoveries ranged from of 92.4\%\–125.7\%.

}, keywords = {direct analysis in real time mass spectrometry, Metal-organic frameworks, SOLID-PHASE MICROEXTRACTION, Sustainable analytical method, Triazine herbicides}, issn = {0003-2670}, doi = {https://doi.org/10.1016/j.aca.2019.04.024}, url = {http://www.sciencedirect.com/science/article/pii/S0003267019304453}, author = {Jiaqin Wang and Qi Du and Xinrui You and Youqi Lv and Wentao Bi and Hongli Li and David D. Y. Chen} } @article {WANG201720, title = {High throughput screening of phenoxy carboxylic acids with dispersive solid phase extraction followed by direct analysis in real time mass spectrometry}, journal = {Analytica Chimica Acta}, volume = {996}, year = {2017}, pages = {20 - 28}, abstract = {Abstract A high throughput, low environmental impact methodology for rapid determination of phenoxy carboxylic acids (PCAs) in water samples was developed by combing dispersive solid phase extraction (DSPE) using velvet-like graphitic carbon nitride (V-g-C3N4) and direct analysis in real time mass spectrometry (DART-MS). Due to the large surface area and good dispersity of V-g-C3N4, the DSPE of PCAs in water was completed within 20~s, and the elution of PCAs was accomplished in 20~s as well using methanol. The eluents were then analyzed and quantified using DART ionization source coupled to a high resolution mass spectrometer, where an internal standard was added in the samples. The limit of detection ranged from 0.5~ng~L-1 to 2~ng~L-1 on the basis of 50~mL water sample; the recovery 79.9{\textendash}119.1\%; and the relative standard deviation 0.23\%{\textendash}9.82\% (>=5 replicates). With the ease of use and speed of DART-MS, the whole protocol can complete within mere minutes, including sample preparation, extraction, elution, detection and quantitation. The methodology developed here is simple, fast, sensitive, quantitative, requiring little sample preparation and consuming significantly less toxic organic solvent, which can be used for high throughput screening of PCAs and potentially other contaminants in water.}, keywords = {direct analysis in real time mass spectrometry, dispersive solid phase extraction, phenoxy carboxylic acids, Velvet-like graphitic carbon nitride}, issn = {0003-2670}, doi = {https://doi.org/10.1016/j.aca.2017.10.007}, url = {http://www.sciencedirect.com/science/article/pii/S0003267017311479}, author = {Jiaqin Wang and Jun Zhu and Ling Si and Qi Du and Hongli Li and Wentao Bi and David Da Yong Chen} }