Abstract: To stabilize flow rate in a single-stroke, syringe-type high pressure pump to a constant value after turn-on, a control system increases the pump speed until equilibrium conditions are reached and then pumps at the preset rate. In one embodiment, the control system senses the maximum rate of change of pressure, detects a pressure when the rate of change is two-thirds of the maximum, increases the pump rate until the pressure is three times that at the value of the detected pressure and begins pumping at the preset constant flow rate.

Abstract: A process for separating an extract component from a raffinate component contained in a feed mixture. A unidirectional fluid flow system is maintained through a series of separating units through which the components travel at different rates. A component concentration distribution is established within the system of units and divided into specific zones. Feed and displacement fluid are passed into the inlets of two of the units and extract and raffinate are taken as the entire streams from outlets of two of the units all at appropriate points on the component concentration distribution. Other inlets and outlets of the various units lying in the same zone are interconnected. At the appropriate times the inlets and outlets are shifted so as to simulate movement of the units in a direction co-current with the fluid flow and thereby enable the inlets and outlets to continually lie in the appropriate zones.

Abstract: (-)-6a,10a-Trans-1-hydroxy-3-n-pentyl-6,6,9-trimethyl-6a,7,8,10a-tetrahydro dibenzo[b,d]pyran or any of its related pyrans in which the n-pentyl group is replaced by hydrogen or C.sub.1 -C.sub.10 alkyl is isolated from a crude synthetic mixture by a process which comprises esterifying the mixture to form perfluorinated alkanoic acid esters, removing low-boiling and non-volatile components, passing the mixture through a first gas chromatographic column with a packing whose liquid phase consists of a slightly polar phenyl-substituted silicone oil and recovering a fraction rich in the desired component, passing the recovered fraction through a second gas chromatographic column with a packing whose liquid phase consists of a non-phenyl-substituted silicone oil and recovering a fraction rich in the desired component, hydrolyzing the fraction recovered from the second stage, and recovering the desired product from the hydrolysis mixture.

Abstract: An improved method is disclosed for the chromatographic separation of soluble components from a multicomponent mixture wherein a feed solution of the multicomponent mixture and a desorbent are sequentially fed under predetermined conditions into column(s) packed with a solid adsorbent.

Abstract: Large-scale apparatus and process for chromatographic separation of fructose/dextrose sugar solutions employing large diameter beds of a strongly cationic salt of an ion exchange resin. The cationic ion exchange resin is densely and uniformly packed in a separation column by means of a resin loading method which includes washing the resin with a salt selected from the group of calcium, barium, strontium or silver salts of the resin. The shrunken resin is then placed in the column to completely fill the column. After sealing the column, excess salt is washed away to thereby expand the resin inside the confined separation column chamber.The uniformly dense packing of the resin in the separation column chamber eliminates the need for mechanical baffles which were formerly required to insure regular and uniform flow throughout the entire cross sectional area of the separation columns.

Abstract: Aqueous solution of weak base (e.g. ammonium hydroxide) incompletely neutralized salt of an inorganic polyacid having three or more replaceable hydrogens also containing 2 to 10 weight percent dissolved alkanol or alkanenitrile buffered to a pH not exceeding 7.5 is a useful mobile phase for liquid chromatographic component separation and content determination of sample containing closely related rather polar compounds by means of a solid phase having a nitrogen-containing exchange base derived from an aminoalkyl-substituted trialkoxysilane. Such mobile phase is superior to prior suggested reverse phase made mobile phases such as 50:50 water and methanol or water and acetonitrile, or acidic aqueous solutions of strong base (e.g. sodium hydroxide) partially neutralized inorganic polyacid having at least three replaceable hydrogens.

Abstract: A silylated silica or alumina covalently bonded to a chiral amino acid through a carboxyl group of said acid may be used as the solid stationary phase in the chromatographic resolution of racemic mixtures. Several classes of derivatives of such bound chiral amino acids also may be used in the resolution of racemates. Such derivatives include N-alkyl and N-acyl derivatives, and esters where the amino acid is a dicarboxylic acid or contains a hydroxy group.

Abstract: A composition comprising a chiral organic amine covalently linked via a carbamate, mercaptocarbamate, or urea linkage to a chain of atoms whose other terminus is covalently bound to a core support may be used as a solid phase chromatographic medium in the separation of racemic mixtures. An example is alpha-methylbenzyl amine bound through a carbamate linkage to a 3-propylsilyl group covalently bonded to an alumina support.

Abstract: An inorganic oxide impregnated with poly(aminostyrene) whose amino groups are covalently bonded to carboxyl groups of chiral organic hydroxy acids may be used as the solid stationary phase in the chromatographic separation of racemic mixtures.

Abstract: Material which can be utilized as the stationary phase in liquid-solid chromatography for the resolution of racemic mixtures comprises an inorganic oxide silylated with a reagent whose remaining terminus is covalently bonded to a chiral hydroxy acid. For example, a 3-aminopropylsilylated silica gel may be reacted with a chiral tartaric anhydride to form a carboxamide linkage by which the chiral acid is covalently bound to the support.

Abstract: A mobile phase supplying method in a liquid chromatography which is characterized in a disposition of a second plunger pump unit, in addition to the conventional way of employing one plunger pump unit (a first pump). The second plunger pump unit is disposed in series with the first plunger pump unit, being connected to the suction side of the first pump with the discharge side of the second pump, in order to synchronously supply the same amount of mobile phase discharged from the first pump to the suction side thereof by the second pump for the purpose of preventing the suction side of the first pump from being exposed to an occurrence of negative pressure. The apparatus for realizing the method is provided, in its double-pumped structure, with a connecting rod having on either end thereof a first and second plungers, between both pump units, which are synchronously and coaxially driven by a common driving system.

Abstract: Provided is a process for analyzing acidic substances by high speed liquid chromatography. An aqueous pH indicator solution is incorporated in an effluent from a column packed with a packing material, and the pH indicator-incorporated effluent is monitored by means of spectrophotometry. As the pH indicator, a sulphon phthalein indicator is used, which is at least slightly soluble in water and has a pH transformation range falling within the pH range of from about 3.0 to about 10.0 and which exhibits, when maintained at a pH lower than the pH transformation range, the minimum transmittance at a wave length of about 420-440 nm and, when maintained at a pH higher than the pH transformation range, the minimum transmittance at a wave length of at least about 558 nm. The packing material is preferably a sulfonated styrene/divinylbenzene copolymer having a total exchange capacity of about 4 to 5 milli-equivalent/gram.

Abstract: An apparatus and method for increasing the throughput of a chromatographic system by passing several samples in seriatim through tandemly connected first and second chromatographic columns. The eluant from the first column is sampled, or fractionated, and fractions of each of the samples are passed through the second column for further separation. A switching of the sampling valve, disposed between the first and second columns, effects such fractioning. The pumping rate for the second column may be different from that of the first column and allows that two or more sample fractions can occupy the second column concurrently. Column efficiency or separation power of the system can be further increased by continuously recycling the fractions through the second column or passing such fractions through a third column which forms a continuous cyclic flow path with the second column via appropriate valve switching. Recycling can be continued until complete separation is achieved.

Abstract: An improved method is disclosed for the chromatographic separation of soluble components from a multicomponent mixture wherein a feed solution of the multicomponent mixture and a desorbent are sequentially fed under predetermined conditions into column(s) packed with a solid adsorbent.