HPLC high performance liquid mobile phase

HPLC (high-performance liquid chromatography) is an instrumental chromatography technique in which the mobile phase is a liquid. Refer to Figure 13.1 and the accompanying discussion for details of the HPLC system. 

Gas chromatography (GC) is one type of partition chromatography it is similar in many ways to other techniques of this kind, such as HPLC (high-performance liquid chromatography), paper chromatography, etc. The distinguishing features are that the mobile phase is a gas and that the motion of the component bands, in the direction of chromatographic development, involves the forced diffusion of the respective substances in their vapor phases. Many of the differences... 

A more sophisticated method of column chromatography is known as HPLC, high-performance liquid chromatography. This employs very fine solid particles which pack closely together. This increases the surface available for adsorption, and so improves the separation, but because the solid particles are packed tightly together, a pump is needed to force the mobile liquid phase through the column. 

The starting point for this chapter is that of the definition of HPLC (high-performance liquid chromatography) adopted by the author namely, that this is a method of separation of the components of a solution effected by the chromatographic process involving a column of solid stationary phase material and a liquid mobile phase in which all of the various components of the system have been designed so as to optimize the separation. In this context, optimization means first and foremost the complete (quantitative) separation of the components but it can also include such separations that are rapid and which have been automated. The key word in this treatment of instrumentation for HPLC is that of design. 

High Performance Liquid Chromatography. Although chiral mobile phase additives have been used in high performance Hquid chromatography (hplc), the large amounts of solvent, thus chiral mobile phase additive, required to pre-equiUbrate the stationary phase renders this approach much less attractive than for dc and is not discussed here. 

As a method of research, has been used high-performance liquid chromatography in reversed - phase regime (RP HPLC). The advantage of the present method is the following the additional information about AIST and FAS composition (homologous distribution) simple preparation of samples (dilution of a CS sample of in a mobile phase). 

This is not the case when high performance liquid chromatography (HPLC) and MS are considered where, due to the incompatibilities of the two techniques, they cannot be linked directly and an interface must be used, with its prime purpose being the removal of the chromatographic mobile phase. Unfortunately, no single... 

High-performance liquid chromatography (HPLC) with a micellar mobile phase or with a selective pre-column or reaction detection system has also been used to determine alkylenebis(dithiocarbamaes). ° Zineb and mancozeb residues in feed were determined by ion-pair HPLC with ultraviolet (UV) detection at 272 nm. These compounds were converted to water-soluble sodium salts with ethylenediaminetetra-acetic acid (EDTA) and sodium hydroxide. The extracts were ion-pair methylated with tetrabuthylammonium hydrogensulfate (ion-pair reagent) in a chloroform-hexane solvent mixture at pH 6.5-8.S. The use of an electrochemical detector has also been reported. ... 

Degasser for high-performance liquid chromatography (HPLC) mobile phase... 

High Performance Liquid Chromatographic (HPLC) Analysis. A Waters HPLC system (two Waters 501 pumps, automated gradient controller, 712 WISP, and 745 Data module) with a Shimadzu RF-535 fluorescence detector or a Waters 484 UV detector, and a 0.5 pm filter and a Rainin 30 x 4.6 mm Spheri-5 RP-18 guard column followed by a Waters 30 x 3.9 cm (10 pm particle size) p-Bondapak C18 column was used. The mobile phase consisted of a 45% aqueous solution (composed of 0.25% triethylamine, 0.9% phosphoric acid, and 0.01% sodium octyl sulfate) and 55% methanol for prazosin analysis or 40% aqueous solution and 60% methanol for naltrexone. The flow rate was 1.0 mL/min. Prazosin was measured by a fluorescence detector at 384 nm after excitation at 340 nm (8) and in vitro release samples of naltrexone were analyzed by UV detection at 254 nm. 

Procedure Flavonoids are then further purified with 2 ml of methanolic HC1 (2 N), followed by centrifugation (2 min, 15 600 g), hydrolyzation of 150 il of suspension in an autoclave (15 min, 120 C). A reverse osmosis-Millipore UF Plus water purification system is used in high performance liquid chromatography (HPLC) with an autosampler. After injections of 5 pg of samples, the mobile phases flow at a rate of 1 ml/minute with isocratic elution in a column at 30 C. 

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