Abstract: To provide performance particularly in handling supercritical extraction systems, a specially designed pump includes a cam-driven, single-plunger with a cam having a profile that enables the pumping system to avoid destructive reverse torque on the cam, gear train and drive motor after the cam passes top dead center. The plunger includes a seal having one side in contact with the supercritical fluid and a mechanism for supporting and aligning the piston on the other side of the seal to maintain the piston in alignment. The piston drive has Hertzian contact with the piston. The fluid volume leaving the pump is determined by measuring only pressure or other parameters related to flow and movement of the plunger. Measurement of the fluid volume leaving the pump is useful for recording or indicating the flow rate while the pump is operating.

Abstract: An apparatus for supercritical extraction is disclosed herein. The apparatus includes a plurality of containers adapted to hold a different one of a corresponding plurality of samples, a first transport means for carrying the plurality of sample containers, and a second transport means for transporting a selected container from the first transport means to a supercritical extractor. The supercritical extractor includes a heating means having a recess for receiving the selected container, means for passing fluid at a supercritical condition through the selected container, and a receiving means for receiving extractant from the selected container. A programming means is provided to control the first and second transport means.

Abstract: An automatic variable-orifice fluid restrictor for use with a supercritical extractor having a collection trap or a supercritical chromatograph includes an inlet line for fluid at a pressure above its critical pressure, an extended tubular probe having an inner and an outer surface and a proximal and a distal end. The proximal end of the probe carries an inlet connected to the inlet line and is outside of the trap. The distal end of the probe includes a variable orifice means adapted for metering the fluid. The variable orifice means is adjacent to the outer surface of the probe and is located in the midst of the trap. The variable orifice means is adjusted by an adjusting stem having first and second ends. The first end of the adjusting stem is connected to automatic control means such as a servo at the proximal end of the probe and outside of the trap. The second end of the adjusting stem varies the area of the orifice by moving a first orifice member.

Abstract: To provide performance particularly in handling supercritical extraction systems, a specially designed pump includes a cam-driven, single-plunger with a cam having a profile that enables the pumping system to avoid destructive reverse torque on the cam, gear train and drive motor after the cam passes top dead center. The fluid volume leaving the pump is determined by measuring only pressure or other parameters related to flow and movement of the plunger. Measurement of the fluid volume leaving the pump is useful for recording or indicating the flow rate while the pump is operating.

Abstract: To inject sample into a capillary tube of an electrophoresis apparatus, a vacuum tank is connected to one end of the tube while the other end is in sample to impart a pressure difference across the tube. The pressure in the pressure chamber is sensed, integrated and used to determine and control the amount of sample drawn and to correct peak data.

Abstract: In a piston pump for pumping liquid carbon dioxide at a temperature below 30 degrees Fahrenheit and pressures at least as high as 7500 psi, the volume leaving the pump is determined by measuring only pressure or other parameter related to flow and movement of the plunger. The position of the piston is measured and the resulting displacement is integrated to determine volume of fluid pumped.

Abstract: In a piston pump for pumping liquid carbon dioxide at a temperature below 30 degrees Fahrenheit and pressures at least as high as 7500 psi at an outlet flow rate in excess of 10 milliliters per minute, the inlet to the pump and the pumphead are each cooled by thermoelectric heat exchangers that are air cooled. The pump is a cam-driven, single-plunger pump with a cam profile that enables the pumping system to avoid distructive reverse torque on the cam, gear train and drive motor after the cam passes top dead center. The volume leaving the pump is determined by measuring only pressure or other parameter related to flow and movement of the plunger. The piston of the pump is supported on both sides of the seal and the support for the piston within the pumphead are machined consentrically and colinearly to the seal gland.

Abstract: To supply supercritical fluid to an automatic supercritical fluid extractor and collect extract from the extractor, sample holding cartridges are lifted one by one in series by an elevator plug into a pressure chamber. An inlet at the top of the cartridge engages a pressure vessel inlet for the extractant so that extractant flows into the cartridge and into the space between the cartridge and inner walls of the pressure chamber. The outlets from the cartridge and pressure vessel communicate with the collector and exhaust through passageways in the plug. The plug has cleaning ports for cleaning seals and the outlet from the cartridge flows past the seals. The collector lifts vials into place and can precool the collection solvent, and later as part of the collection procedure, heat and pressurize the collector.

Abstract: To detect bands in an electrophoresis capillary tube having a liquid separating medium, a light source and a light detector of a monitor are positioned on opposite sides of the capillary tube with the light source transmitting light through a first slit and light passing to the detector through a second slit after it has passed through the capillary tube. The first and second slits are aligned with the direction of motion of bands, have a maximum length of less than 500 micrometers and a maximum width of less than 200 micrometers. There are no vertical lengths in the capillary tube having a dimension greater than one third of its length between a sample injecting end and a detecting end of the capillary tube.

Abstract: To avoid deposits on the restrictor that channels extractant into a collector, a heated capillary tube pressure release restrictor, has a thermally insulated outlet end in a collecting trap substantially colder than the capillary tube. The restrictor is heated between the insulation and the capillary tube by Joulean heating. The solvent in the trap is at a pressure of 5 to 200 psi above atmospheric pressure. The thermal resistance of the insulation is selected to reduce the heat added to the extractant to a minimum and yet cause the temperature of the extractant to be in a range within which it is sufficiently hot so it does not freeze when added to the collection solvent but not so hot as to reduce partitioning of the extract and extractant before the extractant leaves the collection solvent. It has a thermal conductivity no greater than 60 BTU's per hour, per square foot, per inch for a one degree Fahrenheit difference.

Abstract: To control a chemical analyzer, a program counter sequentially energizes the row conductors of a bus-bus type program card, with the columns being connected to a command interpreter prearranged to distinguish between commands not requiring a data input and commands that require a data input. Commands requiring a data input automatically permit sequencing to the next command which is a data readout while inhibiting the outputs from the conductors that provide commands for operations not requiring data such as the operations of raising and lowering pipettes or moving chemical receptacles one position. The data is read through a decoder while the sequencing is temporarily inhibited and the command outputs are inhibited. An additional command is provided by a direct signal from the program counter with no conductive connection between the rows and columns of the program card.

Abstract: To transfer fluids between receptacles at controlled times and temperatures for analysis of the fluids, the receptacles are carried by shuttles which are replaceable and movable within the chemical analyzer and have fluids deposited in them automatically at predetermined times and locations under the control of a program card as they move through temperature-controlled zones at speeds established to keep the receptacles in the temperature-controlled zones long enough to complete a reaction. Two of the shuttles are driven and pull or push the other shuttles in a circular path. In one embodiment, a second circle of shuttles or a reel carrying receptacles moves in the reverse direction from a first group of shuttles so that fluids may be transferred from one receptacle to another at predetermined points to provide greater flexibility in the analyzing apparatus.

Abstract: To compensate for variations in the intensity of light emitted from different locations within a lamp or in different directions from the lamp, a flat, thin, radiating member is positioned to receive intense light from the lamp and to radiate two divergent beams of light with proportional intensities in directions transverse to the member through collimating means oriented on the same light radiating spot. Light from the lamp, in one embodiment, is focused onto a spot on the side of the radiating member opposite the collimating means with an ellipsoidal reflector and, in another embodiment, the required intensity is obtained by positioning a lamp near the side of the radiating member opposite the collimating means.