Abstract: A lost circulation detection device includes a first detection member and a second detection member, a first signal transmitter and a first signal receiver are disposed on the first detection member, and the first signal transmitter transmits a signal along an axial direction of a rockshaft so that the first signal receiver acquires data information of drilling fluid in the axial direction of the rockshaft; a fluid channel penetrating through the second detection member is disposed in the second detection member, and the fluid channel is configurable to be in communication with the rockshaft; a second signal transmitter and a second signal receiver are disposed oppositely on two sides of the fluid channel, and the second signal transmitter transmits a signal along a center line of a second accommodating groove, so that the second signal receiver acquires data information of drilling fluid in a circumferential direction of the rockshaft.

Abstract: The present invention relates to a high performance liquid chromatography method for polypeptide mixtures. Specifically, the method including the following steps: step (1): preparing a solution of the glatiramer acetate to be tested; step (2): performing gradient elution on a sample to be tested with an anion exchange liquid chromatography, a cation exchange liquid chromatography, or a reversed-phase liquid chromatography; step (3): determining a peak area corresponding to each component of the glatiramer acetate, comparing the peak area with to a peak area of a reference substance to determine whether the content of each component of the sample to be tested is in a qualified range.

Abstract: The present invention discloses a method for preparing glatiramer acetate, comprising: (1) dissolving L-alanine NCA, L-tyrosine NCA, L-glutamic acid-?-benzyl ester NCA, and L-?-trifluoroacetyl-lysine NCA in 1,4-dioxane as solvent, stirring until a clarified solution is formed; (2) adding diethylamine for catalysis, stirring at 20-25° C., then slowly pouring the reaction solution into water, collecting the produced white product; (3) adding the obtained product to a solution of hydrobromic acid in acetic acid, stirring at 23.0-25.0° C., pouring the reaction solution into purified water for quenching and stirring, subjecting the mixture to suction filtration to obtain a yellow solid, after repeating 3-5 times, subjecting the solid to blast drying to remove the moisture therein; and (4) dissolving the solid obtained in step (3) in a 1M piperidine aqueous solution at room temperature and stirring, subjecting the obtained solution to dialysis, adding glacial acetic acid to adjust the pH to 5.5-7.

Abstract: The present invention relates to a high performance liquid chromatography method for polypeptide mixtures. Specifically, the method including the following steps: step (1): preparing a solution of the glatiramer acetate to be tested; step (2): performing gradient elution on a sample to be tested with an anion exchange liquid chromatography, a cation exchange liquid chromatography, or a reversed-phase liquid chromatography; step (3): determining a peak area corresponding to each component of the glatiramer acetate, comparing the peak area with to a peak area of a reference substance to determine whether the content of each component of the sample to be tested is in a qualified range.

Abstract: The present invention discloses a method for preparing glatiramer acetate, comprising: (1) dissolving L-alanine NCA, L-tyrosine NCA, L-glutamic acid-?-benzyl ester NCA, and L-?-trifluoroacetyl-lysine NCA in 1,4-dioxane as solvent, stirring until a clarified solution is formed; (2) adding diethylamine for catalysis, stirring at 20-25° C., then slowly pouring the reaction solution into water, collecting the produced white product; (3) adding the obtained product to a solution of hydrobromic acid in acetic acid, stirring at 23.0-25.0° C., pouring the reaction solution into purified water for quenching and stirring, subjecting the mixture to suction filtration to obtain a yellow solid, after repeating 3-5 times, subjecting the solid to blast drying to remove the moisture therein; and (4) dissolving the solid obtained in step (3) in a 1M piperidine aqueous solution at room temperature and stirring, subjecting the obtained solution to dialysis, adding glacial acetic acid to adjust the pH to 5.5-7.