34 results about "Levoglucosan" patented technology

The invention discloses a method for producing levoglucosan by using agricultural and forest waste. The method for producing the levoglucosan by using the agricultural and forest waste comprises the following steps of (1) adding the crushed agricultural and forest waste and water into a hydrothermal reaction kettle according to a mass volume ratio of (1 to 1) to (5 to 20); (2) filling the hydrothermal reaction kettle with CO2, sealing the hydrothermal reaction kettle to make the hydrothermal reaction kettle heated to 150-250 DEG C with stirring, and maintaining the temperature for 10-50 minutes; (3) cooling the hydrothermal reaction kettle, collecting a reaction product, and conducting vacuum filtration, separation and drying on the reaction product to obtain a solid product subjected to hydrothermal pre-treatment; (4) placing the solid product in a pyrolysis reactor to make the solid product subjected to pyrolysis in a CO2 atmosphere; and (5) obtaining a liquid product with a high levoglucosan concentration after conducting fractional condensation on the solid product. According to the method for producing the levoglucosan by using the agricultural and forest waste, hydrothermal pre-treatment under the CO2 atmosphere and pyrolysis under the CO2 atmosphere are combined to promote maximum conversion from the agricultural and forest waste to the levoglucosan, and the defect of alow yield of levoglucosan in bio-oil obtained by directly conducting pyrolysis on biomass is overcome.

A method for synchronously measuring levoglucosan, mannan and galactosan in aerosol for high performance liquid chromatography-tandem quadrupole mass spectrometry combination includes the steps that levoglucosan, mannan and galactosan in an aerosol sample are subjected to ultrasonic extraction with ultrapure water and detected by means of a high performance liquid chromatography-tandem quadrupolemass spectrometer; ammonia water is adopted as a mobile phase; an electrospray ionization mode suitable for polar molecule analysis is adopted as an ion source of a mass spectrometry, ion source parameters and compound parameters optimized many times are adopted in a mass spectrometric method, and qualitative and quantitative analysis is conducted in an anion and multiple-reaction monitoring mode.By means of the external standard curve method, the linear relation of L, M and G is good in the range of 0.01<-1> microgramme per milliliter, the correlation coefficient is larger than 0.99, the detection limit of L is smaller than 0.005 microgramme per milliliter, the detection limits of M and G are both smaller than 0.01 microgramme per milliliter, experiment repeatability is good, relative standard deviations of repetitive experiments of L, M and G are 1.31%, 4.48% and 1.31% respectively, and the adding standard recovery rates of L, M and G all reach 97% or above.

The present invention belongs to the field of biopharmaceuticals, specifically relating to a bound selenium polysaccharide. The polysaccharide uses as a carrier a polysaccharide substance having a 3,6-levoglucosan structure, and a selenium atom connects to a carbon atom at position 6 of a polysaccharide 3,6-inner ether structure by means of a selenoester structure. By means of oxidizing the carbon atom at position 6 of the polysaccharide 3,6-inner ether bond, converting same to a 3,6-lactone, then undergoing ring-opening esterification by reacting with selenocysteine, the prepared structure is well-defined, being a bound selenium polysaccharide product containing a controllable amount of selenium. The prepared bound selenium product is able to noticeably improve the immunity of test subjects by means of increasing blood-selenium content.