CEM Corporation | Date: 2013-06-11
A controlled release and self-resealing vessel assembly for high pressure microwave assisted chemistry is disclosed. The vessel assembly includes a microwave-transparent, heat expandable reaction vessel having at least two cylindrical portions axially adjacent one another, with one of the portions having a diameter larger than the diameter of the other portion. A transition portion is between the two cylindrical portions, the vessel mouth is in the larger-diameter portion, and a cylindrical retaining sleeve surrounds the vessel.
CEM Corporation | Date: 2015-09-22
An instrument for performing microwave-assisted reactions and an associated method are disclosed. The instrument typically includes (i) a microwave-radiation source, (ii) a cavity, (iii) a waveguide in microwave communication with the microwave-radiation source and the cavity, (iv) at least one reaction-vessel sensor for determining the number and/or type of reaction vessels positioned within the cavity, (v) an interface, and (vi) a computer controller. The computer controller is typically in communication with the interface, the microwave-radiation source, and the reaction-vessel sensor. The computer controller is typically capable of determining the output of the microwave-radiation source in response to the number and/or type of reaction vessels positioned within the cavity.
Cem Corporation | Date: 2014-09-23
An instrument and method for accelerating the solid phase synthesis of peptides are disclosed. The method includes the steps of deprotecting a protected first amino acid linked to a solid phase resin by admixing the protected linked acid with a deprotecting solution in a microwave transparent vessel while irradiating the admixed acid and solution with microwaves, activating a second amino acid, coupling the second amino acid to the first acid while irradiating the composition in the same vessel with microwaves, and cleaving the linked peptide from the solid phase resin by admixing the linked peptide with a cleaving composition in the same vessel while irradiating the composition with microwaves.
Cem Corporation | Date: 2013-04-09
A method of measuring NMR response in an NMR instrument includes heating a sample at a heater temperature that is higher than the temperature of the interior of the NMR instrument, positioning the heated sample in the NMR instrument, and measuring the NMR response of the heat sample. Typically, the sample is dry and includes fat. Furthermore, a method of determining an amount of a component of a sample includes positioning a sample in an NMR instrument, applying a sequence of radio-frequency pulses to the sample, measuring the amplitudes of the signals produced by the application of the sequence of radio-frequency pulses, and determining the amount of a component in the sample using the measured amplitudes of the signals. The disclosed methods typically provide accurate analysis of samples in a shorter time period than traditional NMR techniques and solvent-based analysis techniques.
CEM Corporation | Date: 2015-12-16
An instrument and method for high pressure microwave assisted chemistry are disclosed. The method includes the steps of applying microwave radiation to a sample in a sealed vessel while measuring the temperature of the sample and measuring the pressure generated inside the vessel and until the measured pressure reaches a designated set point, opening the vessel to release gases until the pressure inside the vessel reaches a lower designated set point, closing the vessel, and repeating the steps of opening the vessel at designated pressure set points and closing the vessel at designated pressure set points to the sample until the sample reaction reaches a designated high temperature. The designated set points can controllably differ from one another as the reaction proceeds. Microwave energy can be applied continuously or intermittently during the opening and closing steps. The apparatus includes a microwave cavity, a microwave transparent pressure resistant reaction vessel in the cavity, a cap on the reaction vessel, a pressure sensor for measuring pressure in the vessel, a temperature sensor, and means for opening and closing the cap at predetermined pressure set points measured by the pressure sensor to release pressure from the vessel.