Methods for transferring a carbon dioxide based separation procedure from a first chromatographic system to a second one involve identifying an average column pressure for the separation in the first system is identified, determining a measured average column pressure for the separation in the second system, and comparing the measured average column pressure with the identified average column pressures. To more closely match the identified average column pressure, the methods involve: (a) altering a cross-sectional area of a column packed with media in the second system; and/or (b) adding makeup fluid along the length of the column in the second system. Columns with the characteristics used in the methods and second chromatographic systems are disclosed.

A device is provided in a supercritical fluid system, which uses a mobile phase output by a separation device, the mobile phase volumetrically expanding as it decompresses. The device includes a passive splitter and a shuttle valve. The passive splitter is configured to receive the mobile phase and to split the mobile phase into a primary flow stream and a split flow stream, where the primary flow stream is directed to a pressure maintenance device. The passive splitter is further configured to reduce pressure of the split flow stream, causing volumetric expansion of the split flow stream. The shuttle valve is configured to insert volumetric aliquots of the volumetrically expanded split flow stream into a dilution flow stream to provide a diluted split flow stream, and to direct the diluted split flow stream to a low pressure detector.

(EN) In the chromatographic chamber (3), to which the tip (11) enters from below. The tip (11) serves as the end of separate supply lines (5a, 5b, 5c . . . 5x), and each supply line (5a, 5b, 5c . . . 5x) is intended to deliver a separate eluent component. The first supply line (5a) comprises the first reservoir (6a) connected to the first pump (7a), to which the first flexible tube (8a) is connected terminated with the rigid tube (9a). The tip (11) is the first turning point (21) and then, with the use of the three-dimensional machine (2), it is passed along the line to the second turning point (22) and back again, while the individual components are pumped with variable efficiency controlled by the computer (20). This results in a quantitative and qualitative composition in time. At the same time, the position of the moving front is registered with the digital camera (19), and the signals of the eluent front migration distance are registered by the computer (20), and based on this information, the pumps (7a, 7b . . . 7x) that the individual components of the eluent are controlled accordingly. After reaching the final migration of the eluent front, the delivery of the components is stopped, and then the plate (18) is removed from the chromatographic chamber (3) and dried under the hood. As a result, the developed chromatogram is obtained. (19), and the signals of the eluent front migration distance are registered by the computer (20), and based on this information, the pumps (7a, 7b . . . 7x) that deliver individual components of the eluent are controlled accordingly. After reaching the final migration of the eluent front, the delivery of the components is stopped, and then the plate (18) is removed from the chromatographic chamber (3) and dried under the hood. As a result, the developed chromatogram is obtained. (19), and the signals of the eluent front migration distance are registered by the computer (20), and based on this information, the pumps (7a, 7b . . . 7x) that deliver individual components of the eluent are controlled accordingly. After reaching the final migration of the eluent front, the delivery of the components is stopped, and then the plate (18) is removed from the chromatographic chamber (3) and dr

This disclosure provides a method for converting CBD to a tetrahydrocannabinol featuring the use of cheap and non-toxic aluminum isopropoxide as a catalyst. The method comprises (a) providing a reaction mixture comprising a catalyst in an organic solvent, wherein the catalyst comprises aluminum isopropoxide; (b) adding a reagent comprising CBD to the reaction mixture; (c) mixing the reaction mixture and allowing a reaction for converting CBD to a tetrahydrocannabinol to occur for a predetermine period of time; (d) removing the catalyst by filtration upon the completion of the reaction; (e) removing the organic solvent; and (f) eluting the tetrahydrocannabinol from the organic phase.

A method of controlling a liquid chromatograph that estimates the maximum value of the pressure reached during measurement before actually measuring a sample. The method includes a pump having a gradient function that feeds liquid while changing the composition of a plurality of eluents, according to gradient liquid feeding conditions, a sample filling unit for filling a sample, a separation column, an analysis flow channel connecting the pump to the separation column, and a pressure sensor which detects a pressure within the analysis flow channel during liquid feeding by the pump. A maximum pressure presumed during measurement is calculated based on an initial pressure as a pressure within the analysis flow channel when the pump starts feeding liquid and the gradient liquid feeding conditions and that when the maximum pressure presumed is determined to be a predetermined upper pressure limit, the sample filling is not performed.

The present invention relates to the field of RNA analysis. In particular, the invention concerns the use of a catalytic nucleic acid molecule for the analysis of an RNA molecule. The invention concerns methods for analyzing the 5 terminal structures of an RNA molecule having a cleavage site for a catalytic nucleic acid molecule. In particular, the invention concerns a method for determining the presence of a cap structure in an RNA molecule having a cleavage site for a catalytic nucleic acid molecule, a method for determining the capping degree of a population of RNA molecules having a cleavage site for a catalytic nucleic acid molecule, a method for determining the orientation of the cap structure in a capped RNA molecule having a cleavage site for a catalytic nucleic acid molecule and a method for determining relative amounts of correctly capped RNA molecules and reverse-capped RNA molecules in a population of RNA molecules, wherein the population comprises correctly capped and/or reverse-capped RNA molecules that have a cleavage site for a catalytic nucleic acid molecule. Moreover, the present invention provides uses of a catalytic nucleic acid molecule.

Systems, methods and devices are taught for providing analytical methods for peak-shaped responses separated in time or space, including quantitation of chromatographic peaks based on a width measurement of a peak trace at a selected height as a quantitation element. Methods of treating a peak trace as a composition of exponential functions representing a leading and a trailing end are included. Methods that facilitate the detection of impurities in peak trace outputs are also included.

A method for monitoring a fluidic system of a liquid chromatography system is characterized by: (a) drawing a fluid into a syringe pump; (b) configuring a valve so as to fluidically couple the pump to either a fluidic pathway through the fluidic system or to a plug that prevents fluid flow; (c) causing the syringe pump to progressively compress the fluid therein or expel the fluid to the fluidic pathway, while measuring a pressure of the fluid; (d) determining a profile of the variation of the measured pressure; (e) comparing the determined profile to an expected profile that depends upon the fluid; and (f) providing a notification of a sub-optimal operating condition or malfunction if the determined profile varies from the expected profile by greater than a predetermined tolerance.

High accuracy mixing of fluids in a disposable fluid processing system with at least two pumps is provided by a method where a calibration fluid volume is pumped through each pump via a flow meter at at least one calibration pump speed while registering the flow rate using data output from the flow meter, a pump calibration function is calculated from the calibration pump speed and flow rate data and two or more operation fluids are mixed to a predetermined mixture ratio and predetermined flow rate by controlling the pump speed of the respective pumps in accordance with the pump calibration functions.

The present disclosure relates to an apparatus for regulating the average mobile phase density or pressure in a carbon dioxide based separation system. The apparatus includes a controller, a set of pressure or density sensors and a set of instructions capable of determining the pressure drop across a column and adjusting at least one system component or parameter to achieve a pre-determined average mobile phase density or pressure in the system.