HPLC, high performance liquid chromatograph

Quantitative Analysis of Irreversible Kinetic Resolution. Enantiomeric excess (ee) is the measure of enantiopurity, and the value is most often determined by chiral GC (gas chromatograph equipped with a chiral column) or HPLC (high performance liquid chromatograph equipped with a chiral column) methods. Enantiomeric excess is the ratio of the concentration difference of the enantiomers to the total concentration as shown in equation 1 for the substrate and the product enantiomers. The value is mostly expressed by multiplying with 100 to get the percentage value. In kinetic resolution, ees of the less reactive substrate enantiomer [S ] and eep of the product enantiomer depend on the progress (conversion) of the reaction. 

Coupling of analytical techniques (detectors) to high-performance liquid chromatographic (HPLC) systems has increased in the last tree decades. Initially, gas chromatography was coupled to mass spectrometry (MS), then to infrai ed (IR) spectroscopy. Following the main interest was to hyphenate analytical techniques to HPLC. 

Figure 9 shows the result of injecting 10 gA of the total low molecular weight fraction from GPC 1 (Column Code A2) into GPC 2 (Column Code Bl). With this column code, GPC 2 is performing as a High Performance Liquid Chromatograph (HPLC). Separation is based upon solubility (i.e. composition differences) rather than upon molecular size. Methyl methacrylate monomer was used as a reference and added to the solution injected into GPC 1. Concentrations of n-butyl methacrylate, styrene and conversion are readily calculated from the peak areas and initial concentrations. 

High-performance liquid chromatographic determination Inject an aliquot (Vi) of the soil and crop samples into the HPLC system. 

Reversed-phase high-performance liquid chromatography (HPLC) column 50 mm x 3.2-mm i.d. with Kromasil 5- um Gig packing High-performance liquid chromatograph coupled to a triple-quadrupole mass spectrometer with an atmospheric pressure chemical ionization (APCI) source Gel permeation chromatograph with a 60 mm x 25-mm i.d. column packed with Bio-Beads SX-3 (50-g)... 

Inject an aliquot of the HPLC-ready sample solution into the high-performance liquid chromatograph. 

High-performance liquid chromatograph with degasser and column oven HPLC autosampler... 

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. 

Figure 30.1 Flow Diagram of a High-Performance Liquid Chromatograph (HPLC).

R. G. Strickley, M. Brandi, K. W. Chan, K. Straub, L. Gu, High-Performance Liquid Chromatographic (HPLC) and HPLC-Mass Spectrometric (MS) Analysis of the Degradation of the Luteinizing Hormone-Releasing Hormone (LH-RH) Antagonist RS-26306 in Aqueous Solution , Pharm. Res. 1990, 7, 530-536... 

Table 1 gives an overview of potential factors to be considered when performing a robustness test on a capillary electrophoretic (CE) method. In references 6, 9, 17, and 19, lists of factors for high-performance liquid chromatographic (HPLC), gas chromatographic (GC), and/or thin-layer chromatographic (TLC) methods, can be found. 

First, the low boiling point (37 C) can lead to handling difficulty. We found it necessary to replace the Waters 6000A pump in the Waters Model 244 high performance liquid chromatograph (HPLC) with a Waters M45 pump to avoid an occasional interruption in flow which we assured to be caused by vapor lock. Second, there are health hazards associated with the use of HFIP, and hygenlc laboratory procedures should be followed. The system should not be used prior to consulting the HFIP Product Information and Material Safety Data Sheet from Du Pont. 

Rao et al. reported a high performance liquid chromatographic method to determine diloxanide furoate and metronidazole in single and in combined dosage forms [41]. A 30 mg equivalent of diloxanide furoate and 25 mg of metronidazole (either as the bulk drug substances or in powdered tablets) was dissolved in methanol, amidopyrine added as the internal standard, and the mixture analyzed by HPLC at room temperature. The analytical column (30 cm x 3.9 mm) consisted of p-Bondapak Cig, with 9 9 1 1 methanol water 0.05 M KH2PO4 0.05 M NaH2P04 as the mobile phase. The flow rate was 1 mL/min), and detection was performed at 254 nm. 

Ciccolini J, Mercier C, Blachon MF et al. A simple and rapid high-performance liquid chromatographic (HPLC) method for 5-fluorouracil (5-FU) assay in plasma and possible detection of patients with impaired dihydropyrimidine dehydrogenase (DPD) activity. J Clin Pharm Ther 2004 29 307-315. 

Often, treatment of samples with fluorescence labeling agent reacts with primary and secondary amines to give a fluorescent compound. This is especially important for detecting amino acids in protein hydrolyzates. Fluorescence detectors may also be integrated into a high performance liquid chromatographic (HPLC) system. 

Electrospray Ionization (ESI) Electrospray ionization involves placing an ionizing voltage—several kilovolts—across the nebulizer needle attached to the outlet from a high-performance liquid chromatograph (HPLC). 

A review of high-performance liquid chromatographic (HPLC) instrumentation, techniques, and methodologies for the determination of trace organic compounds in water is presented. The review includes approaches to sample cleanup or analyte isolation for those compounds likely to be candidates for analysis by HPLC. Column technology, as it contributes to the use of HPLC for trace organic analyses, is discussed. Finally, various techniques for quantitative and qualitative detection of analytes are discussed. 

High-performance liquid chromatograph (HPLC) with fluorescence detector (excitation 290 nm, emission 330 nm) or UV detector (295 nm)... 

High-performance liquid chromatograph (HPLC Perkin-Elmer) with ... 

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