A dual-excitation laser modulation technique for the sensitive measurement of photosensitizers in tumor is proposed. The technique is based on the difference in optical absorption properties of photosensitizers and biological tissues at 405 nm and 450 nm. The 405 nm and 450 nm laser beams, with the same modulation frequency and 180° phase difference, were coupled into a single fiber simultaneously. A periodic signal with a frequency of 1 kHz was generated in alternating excitation, and was processed by phase sensitive detectors. The weak photosensitizer fluorescence masked by tissue autofluorescence can be effectively separated through the proposed method, so that the final signal intensity is only related to the concentration of photosensitizer. The method with a sensitivity of 0.22 mL/ng was determined by measuring the low concentration of protoporphyrin IX (PpIX) solution, and the detection limit of instrument reached 0.5 ng/mL. The puncturable optical probe with a diameter of 675 µm ensures that PpIX in can be detected with spatial resolution, which was performed in the measurement of PpIX in tumor bearing nude mice .
Huangqi Guizhi Wuwu decoction (HGWD), as a classical formula, has been used for thousands of years in China. In this work, a comprehensive strategy was proposed for characterizing the chemical profile of HGWD based on online two-dimensional hydrophilic interaction and reversed-phase liquid chromatography coupled with hybrid linear ion trap-Orbitrap mass spectrometry (online HILIC × RP-ESI/HRMS/MS n ). The compounds in HGWD were first separated by the combined use of an XBridge amide column (150 × 4.6 mm, 3.5 μm) and Accucore C18 column (50 mm × 4.6 mm, 2.6 μm). Modulation with assistant technology, including trap columns and online dilution, was optimized and developed to decrease potential analyte loss and improve the resolution of the system. Subsequently, the accurate mass was determined by high-resolution Orbitrap and MS n fragment data by a hybrid linear ion trap (LTQ). In total, 170 chemical constituents were unambiguously identified or tentatively characterized in both positive and negative ion modes. Our study demonstrated that the proposed online HILIC × RP system coupled to the LTQ-Orbitrap MS platform is an efficient analytical technique for characterizing the chemical profile of multicomponent systems.
危险品化学品经营许可证（带存储）