ABSTRACT
Alginate is a commercially important polysaccharide composed of mannuronic acid and its C5 differential isomer guluronic acid. Comprehensive research on alginate and alginate lyases requires efficient and precise analytical methods for alginate oligosaccharides. In this research, high-performance anion exchange chromatography (HPAEC) in parallel with pulsed amperometric detection (PAD) and mass spectrometry (MS) was applied to the analysis of oligosaccharides obtained by alginate lyase. By optimizing the chromatographic conditions including mobile phase concentration, flow rate, and elution gradient, the analysis of a single sample could be completed in 30 min. Seven unsaturated alginate oligosaccharides were separated and identified through their analysis time observed with PAD, including all structurally different unsaturated disaccharides and trisaccharides. The quantitative analysis of seven oligosaccharides was performed based on the quantitative capability of PAD. The method exhibited adequate linearity and precision parameters. All the calibration curves showed good linearity at least in the concentration range of 0.002 to 0.1 mg/mL. The HPAEC-PAD/MS method provides a general and efficient online method to analyze alginate oligosaccharides.
Subject(s)
Alginates , Mass Spectrometry , Oligosaccharides , Alginates/chemistry , Oligosaccharides/analysis , Oligosaccharides/chemistry , Chromatography, Ion Exchange/methods , Mass Spectrometry/methods , Chromatography, High Pressure Liquid/methods , Polysaccharide-Lyases/chemistry , Polysaccharide-Lyases/metabolism , Hexuronic Acids/chemistry , Hexuronic Acids/analysis , Limit of DetectionABSTRACT
Stray light is a key issue that must be considered in the TianQin telescope. To solve the problem of a long simulation time and the inability of the simulation results to be fed back to guide the optical design, we propose a fast estimation method for stray light based on the FOV with high accuracy. Compared to other models, the error between our model and the software simulation results is smaller, within one order of magnitude. Based on this method, we obtain the optical component target of the TianQin telescope and propose an optimization method to reduce stray light, which can be verified by analyzing the optimized optical design.
ABSTRACT
The temperature sensor is the core part of the temperature measurement instrument, and its performance directly determines the temperature measurement accuracy. Photonic crystal fiber (PCF) is a new type of temperature sensor with extremely high potential. In this paper, we propose a high-performance, structurally simple, liquid-filled PCF temperature sensor, which is based on a SMF-PCF-SMF (single mode fiber, SMF) sandwich structure. By adjusting the structural parameters of the the PCF, it is possible to obtain optical properties that are superior to those of ordinary optical fibers. This allows for more obvious responsive changes of the fiber transmission mode under small external temperature changes. By optimizing the basic structure parameters, a new PCF structure with a central air hole is designed, and its temperature sensitivity is -0.04696â nm/°C. When filling the air holes of PCFs with temperature-sensitive liquid materials, the response of the optical field against the temperature fluctuations can be effectively enhanced. The Chloroform solution is used to selectively infiltrate the resulting PCF owing to its large thermo-optical coefficient. After comparing various filling schemes, the calculation results show that the highest temperature sensitivity of -15.8â nm/°C is finally realized. The designed PCF sensor has a simple structure, high-temperature sensitivity, and good linearity showing great application potential.
