摘要:
The invention relates to a method for determining the concentration of asymmetric dimethylarginine (ADMA) simultaneously with arginine and with symmetric dimethylarginine (SDMA) in biological samples by means of HPLC-MS-MS. The sample preparation consists exclusively of adding a solution of isotope-labeled internal standards (13C6-arginine and D6-ADMA) and of adding a mixture consisting of acetonitrile / propionic acid / trifluoroacetic acid for precipitating high-molecular proteins, the quantity and composition being realized in such a manner that a bringing of the sample composition in line with the composition of the mobile phase in the HPLC separation is achieved without requiring a derivitization or extraction of the analytes. The chromatographic separation of the analytes ensues on a silica normal phase HPLC column while using a mobile phase consisting of water / acetonitrile / propionic acid / trifluoroacetic acid, the volume ratio of water to acetonitrile ranging from 2 to 98 to 30 to 70, the volume percent of trifluoroacetic acid ranging from 0.01 to 0.5, the volume percent of propionic acid being 10 to 100 times higher than trifluoroacetic acid, and the optimized composition of the mobile phase consists of acetonitrile / propionic acid / trifluoroacetic acid with 10 / 90 / 1 / 0.025 volume percents. The detection and quantification ensue by means of tandem mass spectrometry with the following fragmentations being observed: 175.2 m/z → 70.1 m/z for arginine, 181.2 m/z → 74,1 m/z for 13C6-arginine, 203.2 m/z → 172.1 m/z for SDMA, 203.2 m/z → 46.1 m/z for ADMA and 209.2 m/z → 70.1 m/z D6-ADMA.
摘要:
The invention relates to a multiplex transceiver for polymer fibre transmission and method for production thereof. The multiplex transceiver comprises a base body with a recess, in which input and output channels and a dispersion unit are arranged, both the base body with recess and the dispersion unit being injection moulded pieces. According to the method for production of a multiplex transceiver for polymer fibre transmission with one or more input and output channels and a dispersion unit, in a first method step, the base body is produced as an injection moulded piece with a recess and, in a second method step, the dispersion unit is introduced into the recess of the base body also by injection moulding.
摘要:
The invention relates to active substance fractions produced from Rheum species for the inactivation of viruses and disinfection. The active substance fractions are obtained by extraction of the dried and ground root samples with methanol, the aqueous phase so produced is liberated from lipophilic accompanying substances while completely removing the methanol, the purified aqueous phase is extracted by shaking with ethyl acetate and the combined ethyl acetate phase is separated by column chromatography to give a limited number of active substance fractions and the active substance fractions having the same spectrum of constituents are combined.
摘要:
The invention relates to a method for determining the concentration of asymmetric dimethylarginine (ADMA) simultaneously with arginine and with symmetric dimethylarginine (SDMA) in biological samples by means of HPLC-MS-MS. The sample preparation consists exclusively of adding a solution of isotope-labeled internal standards ( 13 C 6 -arginine and D 6 -ADMA) and of adding a mixture consisting of acetonitrile / propionic acid / trifluoroacetic acid for precipitating high-molecular proteins, the quantity and composition being realized in such a manner that a bringing of the sample composition in line with the composition of the mobile phase in the HPLC separation is achieved without requiring a derivitization or extraction of the analytes. The chromatographic separation of the analytes ensues on a silica normal phase HPLC column while using a mobile phase consisting of water / acetonitrile / propionic acid / trifluoroacetic acid, the volume ratio of water to acetonitrile ranging from 2 to 98 to 30 to 70, the volume percent of trifluoroacetic acid ranging from 0.01 to 0.5, the volume percent of propionic acid being 10 to 100 times higher than trifluoroacetic acid, and the optimized composition of the mobile phase consists of acetonitrile / propionic acid / trifluoroacetic acid with 10 / 90 / 1 / 0.025 volume percents. The detection and quantification ensue by means of tandem mass spectrometry with the following fragmentations being observed: 175.2 m/z ? 70.1 m/z for arginine, 181.2 m/z ? 74,1 m/z for 13 C 6 -arginine, 203.2 m/z ? 172.1 m/z for SDMA, 203.2 m/z ? 46.1 m/z for ADMA and 209.2 m/z ? 70.1 m/z D 6 -ADMA.
摘要:
The invention relates to antioxidant substance fractions produced from Rheum species for formulations for the therapy and prophylaxis of inflammatory or autoimmune diseases and/or diseases with disturbed keratinocyte proliferation. The active substance fractions are obtained by extraction of the dried and ground root samples with methanol, the aqueous phase so produced is liberated from lipophilic accompanying substances while completely removing the methanol, the purified aqueous phase is extracted by shaking with ethyl acetate, the resulting aqueous phase and the combined ethyl acetate phase are processed separately, separated by column chromatography to give a limited number of active substance fractions and the active substance fractions from the aqueous phase and from the ethyl acetate phase having the same spectrum of constituents are each combined.
摘要:
The invention relates to a method for the separation of polymer mixtures and a device for carrying out said method, of application to the separation of polymer mixtures on processing thermoplastic plastics. According to the invention, a polymer mixture for separation is fused or plastified in a shear gap of a shear element with annular flow channels of varying diameter, whereby fractions of the polymer mixture are led off from the screw gap in at least two locations, which have annular flow paths of varying diameter. The device comprises a separating chamber (1) with conical inner walls, in the middle of which a rotating mixing rotor (2) with an outer conical form is mounted to form a shear gap (3), whereby the device is provided with one introduction channel (4) and at least two outlet channels (5).