Abstract: To provide a protective coat on a refrigerated sample collector for a corrosive environment a unitary frame includes a support unit with condenser and evaporator coils mounted to the support unit and an orifice connecting the condenser and evaporator coils. The evaporator coils, condenser coils and restrictor are powder coated after being connected, whereby an effective seal is provided for the restrictor, condenser coils and evaporator coils after they are assembled to the support. The unitary frame can be easily removed or connected as a unit to the sample collector. A peristaltic pump may be used for drawing at least one sample into the refrigerated sample collector and depositing said sample into at least one sample bottle. The peristaltic pump may include contoured tube guides to reduce movement of the peristaltic pump as a roller paddle rotates.

Abstract: To provide a protective coat on a refrigerated sample collector for a corrosive environment a unitary frame includes a support unit with condenser and evaporator coils mounted to the support unit and an orifice connecting the condenser and evaporator coils. The evaporator coils, condenser coils and a restrictor are powder coated after being connected, whereby an effective seal is provided for the restrictor, condenser coils and evaporator coils after they are assembled.

Abstract: A sample injector includes a rotary valve element with a straight passageway through it, which element may be rotated to connect a port communicating with a source of solvent with a port communicating with an inlet to a column. Another passageway connects two adjacent ports. The valve element may be rotated to one position in which it provides a straight path for sample to be injected, a second position in which it provides a path that connects a source of purge gas to the chromatographic system and a third position in which it provides a path that connects solvent to the column for preconditioning.

Abstract: A column for flash chromatography having spherical, or semi-spherical, and porous silica gel having a granule size between 3 and 45 ?m and pores between 30 and 300 ?.

Abstract: A remote sensor and associated data processor, performs concurrent analysis of backscattered signals from a multi-beam (6-10) acoustic Doppler emitter/receiver (1) positioned against the inside wall of a conveying pipe (2) or channel. Range-gating of the return signals allows independent analysis of discrete volumes of backscattered signal data corresponding to the distribution, concentration and travel velocity of small individual volumes or bins of water and suspended solids (4). Velocity is derived from the measured Doppler frequency shift for each bin. Relative solids concentration is estimated as a function of the measured intensity of the backscattered signals.

Abstract: The bottle rack for the sample collector is made by injection molding two halves of the rack each of which has a matching surface and a bottle positioning surface. The matching surfaces are fastened together by placing the matching surfaces together back to back whereby locating members are spaced apart a sufficient. To warm a compressor to a starting temperature during cold weather, the ambient temperature is measured and when the ambient temperature is lower than a preset temperature and the compressor is not running, current is applied to the motor windings to warm the compressor.

Abstract: “A measuring instrument includes a transducer for measuring the depth of liquid and a transducer for measuring a physical parameter that causes interference error. A calibration polynomial is used to correct the output signal. The calibration polynomial includes the signal generated by the transducers as independent variables and the output signal as the dependent variable. The calibration polynomial is formed by a correction polynomial having at least one primary measurement signal and at least a first interference related signal as independent variables and a calibrated signal as a dependent variable. To form the calibration polynomial, a preliminary calibration polynomial including the primary independent variable and at least one interference related independent variable is developed. A plurality of data sets is generated from a test fixture. This data is used to eliminate the least significant terms of the preparatory calibration polynomial and to add the most significant cross terms”.

Abstract: A measuring instrument includes a transducer for measuring the depth of liquid and a transducer for measuring a physical parameter that causes interference error. A calibration polynomial is used to correct the output signal. The calibration polynomial includes the signal generated by the transducers as independent variables and the output signal as the dependent variable. The calibration polynomial is formed by a correction polynomial having at least one primary measurement signal and at least a first interference related signal as independent variables and a calibrated signal as a dependent variable. To form the calibration polynomial, a preliminary calibration polynomial including the primary independent variable and at least one interference related independent variable is developed. A plurality of data sets is generated from a test fixture. This data is used to eliminate the least significant terms of the preparatory calibration polynomial and to add the most significant cross terms.

Abstract: A bubbler is positioned within a solvent reservoir of a chromatographic system with its opening near the bottom of the system to measure the pressure of solvent. The bubbler may use air or may use helium or some other gas so that the solvent can be purged of excess air while its level is being monitored by the bubbler. The bubbler provides a depth signal to a microcontroller that records the drop in pressure and projects a low level of pressure at which point solvent should be replenished. The microprocessor may provide a signal to the operator or terminate operation or automatically replenish solvent depending upon the program.

Abstract: Purchase orders for chromatographic columns and sampler tubing are entered into based on estimating usage for a year. An initial partial shipment is made of tagged columns or tubing as the tubing or columns are used. An RFID transmits trigger signals until an order point is reached at which time a new partial shipment is made. This process is repeated until the end of the year.

Abstract: A bubbler is positioned within a solvent reservoir of a chromatographic system with its opening near the bottom of the system to measure the pressure of solvent. The bubbler may use air or may use helium or some other gas so that the solvent can be purged of excess air while its level is being monitored by the bubbler. The bubbler provides a depth signal to a microcontroller that records the drop in pressure and projects a low level of pressure at which point solvent should be replenished. The microprocessor may provide a signal to the operator or terminate operation or automatically replenish solvent depending upon the program.

Abstract: To form a smooth gradient and a preparatory liquid chromatographic system having a plurality of syringe type pumps, solvents are alternately drawn and inserted into each cylinder. The solvents are alternately drawn into and through a long narrow path formed of tubing to create axial mixing and spreading out of the interface and then are drawn into the cylinders during the refill stroke of the piston at a sufficiently high velocity to create turbulence. The drawing of the solvents into one side of the cylinder a radial distance from the center creates circular eddy currents.

Abstract: A liquid chromatographic system includes columns, column mounting fixtures to which the columns are mounted, a detector, a collector, a controller and a plurality of RFIDs. A first RFID communicates with the controller and cooperating RFIDs mounted to other components provide information such as the history of components, parameters and the like. They also receive information from sensors relating to the operation of the liquid chromatograph, store the information and transmit it.

Abstract: A sample injector includes a rotary valve element with a straight passageway through it, which element may be rotated to connect a port communicating with a source of solvent with a port communicating with an inlet to a column. Another passageway connects two adjacent ports. The valve element may be rotated to one position in which it provides a straight path for sample to be injected, a second position in which it provides a path that connects a source of purge gas to the chromatographic system and a third position in which it provides a path that connects solvent to the column for preconditioning.

Abstract: A liquid chromatographic system includes columns, column mounting fixtures to which the columns are mounted, a detector, a fraction collection system, a controller and a plurality of RFIDs. A first RFID communicates with the controller and cooperating RFIDs mounted to other components including the fraction collector to provide information such as the history of components, parameters and the like useful in maintaining inventory control and managing the system. They also receive information from sensors relating to the operation of the fraction collector including the location of sample containers.

Abstract: A liquid chromatographic system includes columns, column mounting fixtures to which the columns are mounted, a detector, a collector, a controller and a plurality of RFIDs. A first RFID communicates with the controller and cooperating RFIDs mounted to other components provide information such as the history of components, parameters and the like. They also receive information from sensors relating to the operation of the liquid chromatograph, store the information and transmit it. Moreover, the RFIDs may substitute for hard wiring in many applications and may enable a central computer to control several liquid chromatographic systems.

Abstract: The bottle rack for the sample collector is made by injection molding two halves of the rack each of which has a matching surface and a bottle positioning surface. The matching surfaces are fastened together by placing the matching surfaces together back to back whereby locating members are spaced apart a sufficient distance. To warm a compressor to a starting temperature during cold weather, the ambient temperature is measured and when the ambient temperature is lower than a preset temperature and the compressor is not running, current is applied to the motor windings to warm the compressor.

Abstract: A chromatographic monitor includes an array of flow cells with individual light sensors that are collectively an array of photodiodes. The output from the photodiodes are multiplexed. To prevent losing information, the photodiodes are each connected to a different one of a plurality of inputs to the multiplexer through a corresponding one of a plurality of circuits that stores energy during the time the one inlet is not connected through the multiplexer to the signal processing circuitry that forms a part of an absorbance monitor. Preferably, the energy storing circuit is a non-switching circuit with low bandwidth and a flat-topped response to an impulse. This improves the signal to noise ratio. A one pole low pass filter with a (1-1/e) Dirac pulse fall time and equal to the multiplex entire cycle repeat time can perform this function and a one pole low pass filter provides satisfactory results.

Abstract: To provide a protective coat on a refrigerated sample collector for a corrosive environment a unitary frame includes a support unit with condenser and evaporator coils mounted to the support unit and an orifice connecting the condenser and evaporator coils. The evaporator coils, condenser coils and a restrictor are powder coated after being connected, whereby an effective seal is provided for the restrictor, condenser coils and evaporator coils after they are assembled to the support. The unitary frame can be easily removed or connected as a unit to the sample collector. The bottle rack for the sample collector is made by injection molding two halves of the rack each of which has a matching surface and a bottle positioning surface. The matching surfaces are fastened together by placing the matching surfaces together back to back whereby locating members are spaced apart a sufficient distance. To position a distributor in the sample collector, an index disk rotates with the distributor.

Abstract: An isocratic gradient profile is inserted into a gradient profile during a flash chromatographic run when TLC indicates that it will be difficult to separate the component being purified from its closest impurity by a gradient. TLC is utilized to determine at least two retention factors with two significantly different solvent strengths for the same solvent system. The two or more retention factors are used to determine a solvent strength in which the retention factor of a target component and the retention factor of a closest impurity are within 0.8 of each other. The isocratic gradient profile is started when this solvent strength is reached during the gradient chromatographic run.