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TiO2 nanowire photocatalyst for dual-ion production in laser desorption/ionization (LDI) mass spectrometry
摘要： It has been challenging to detect small analytes in both positive and negative ion modes using organic matrices in conventional matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). Herein, TiO2 nanowires are presented as a solid matrix to form dual-ion of analytes regardless of chemical properties and to demonstrate the versatile applicability in LDI-MS.
关键词： LDI-MS,TiO2 nanowires,photocatalytic activity,dual-ion production,small analytes detection
更新于2025-09-23 15:19:57
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Matrix free laser desorption ionization mass spectrometry as an efficient tool for the rapid detection of opiates in crude extracts of <i>Papaver somniferum</i>
摘要： Having a long history of traditional medicinal applications, Papaver somniferum is also known as a source of various pharmacologically highly active opiates. Consequently, their detection from plant extracts is an important analytical task and generally addressed by methods of GC and LC-MS. However, opiates do also show structural similarities to matrix molecules used in matrix assisted laser desorption ionization and may therefore ionize upon simple laser irradiation. Following this analytical approach, the present work thoroughly evaluated the direct detection of opiates by matrix free laser desorption ionization (LDI) from crude extracts of P. somniferum. The method facilitated the identification of ten reported opiates by their molecular formulae without any chromatographic pre-purification. Moreover a principal component analysis based on LDI-MS data permitted the correct grouping of all extracts according to their inherent chemistry. Concluding experiments on serial dilutions of thebaine further evaluated potential quantitative applications of the method. Overall results highlight the promising potential of LDI-MS for the swift detection of opiates from complex mixtures.
关键词： LDI-MS,LC-MS,Papaver somniferum,quantification,PCA,opiates detection
更新于2025-09-12 10:27:22
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Synergistic Effect of Metal-Organic Framework/Gallic Acid in Enhanced Laser Desorption/Ionization Mass Spectrometry
摘要： Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has become an indispensable tool for high throughput analysis of macromolecules, but many challenges still remain in detection of small molecules due to the severe matrix-related background interference in the low-molecular mass ranges (MW < 700 Da). Herein, a gallic acid (GA)-functionalized zirconium1,4-dicarboxybenzene metal-organic framework (MOF) (denoted as UiO-66-GA) was designed to serve as a new substrate and a novel strategy on the basis of the synergistic effect of MOF and GA was developed to enhance LDI process. In comparasion with conventional organic matrices, the UiO-66-GA substrate showed superior LDI performance in the analysis of a wide varity of molecules including amino acids, unsaturated fatty acids, bisphenols (BPs), oligosaccharides, peptides, protein, and polyethylene glycol (PEG) of various average molecular weights from 200 to 10000. Perfluorooctanoic sulfonate (PFOS) was used to evaluate the ability of quantitative analysis and its corresponding limit of detection (LOD) as low as 1 fmol was achieved. High sensitivity and good salt tolerance of the UiO-66-GA-assisted LDI-MS were allowed to determine ultratrace PFOS in the spiked human urine and serum samples. In addition, the synergistic mechanism of MOF and GA in enhanced LDI process was investigated by comprehensively comparing GA- and its analogues functionalized UiO-66, and the results revealed that two aspects contributed to the enhanced LDI process: 1) an enhancement in metal-phenolic coordination system of UiO-66-GA promoted laser absorption and energy transfer; 2) introduction of carboxyl- and hydroxyl groups of GA onto UiO-66 facilitated the LDI process in both positive- and negative ion modes. This work expands a new domain for the MOF applications and provides a promising alternative for various molecule analysis.
关键词： LDI-MS,macromolecules,Synergistic effect,UiO-66-GA,small molecules
更新于2025-09-11 14:15:04