Chromatography ultraviolet absorbance

C.W. Huck, M.R. Buchmeiser and G.K. Bonn, Fast analysis of flavonoids in plant extracts by liquid chromatography-ultraviolet absorbance detection on poly(carboxylic acid)coated silica and electrospray ionization tandem mass spectrometric detection. J. Chromatogr.A 943 (2002) 33-38. 

Pihlainen, K. and Kostiainen, R., Effect of the eluent on enantiomer separation of controlled drugs by liquid chromatography-ultraviolet absorbance detection-electrospray ionisation tandem mass spectrometry using vancomycin and native fi-cyclodextrin chiral stationary phases, J. Chromatogr. A, 1033, 91, 2004. 

Widmer N et al (2004) Determination of imatinib (gleevec) in human plasma by solid-phase extraction-liquid chromatography-ultraviolet absorbance detection. J Chromatogr B Analyt Technol Biomed Life Sci 803 285-292... 

Analytical Techniques. Sorbic acid and potassium sorbate are assayed titrimetricaHy (51). The quantitative analysis of sorbic acid in food or beverages, which may require solvent extraction or steam distillation (52,53), employs various techniques. The two classical methods are both spectrophotometric (54—56). In the ultraviolet method, the prepared sample is acidified and the sorbic acid is measured at 250 260 nm. In the colorimetric method, the sorbic acid in the prepared sample is oxidized and then reacts with thiobarbituric acid the complex is measured at - 530 nm. Chromatographic techniques are also used for the analysis of sorbic acid. High pressure Hquid chromatography with ultraviolet detection is used to separate and quantify sorbic acid from other ultraviolet-absorbing species (57—59). Sorbic acid in food extracts is deterrnined by gas chromatography with flame ionization detection (60—62). 

Paper chromatography (benzene-chloroform 1 1—formamide system) of representative chromatogram fractions indicates the presence of a small quantity of a more polar ultraviolet absorbing component that gives a negative blue tetrazolium test and a very polar component (no ultraviolet negative tetrazolium test). These materials have not been characterized. 

He, Y., Yeung, E.S., Chan, K.C., Issaq, HJ. (2002). Two-dimensional mapping of cancer cell extracts by liquid chromatography-capillary electrophoresis with ultraviolet absorbance detection. J. Chromatogr. A 979, 81-89. 

High performance liquid chromatography is used to determine the purity of calcitriol, and to separate it from related compounds. Using a 10 micron silica column of 25 cm length, and a mobile phase of spectroquality heptane ethyl acetate. methanol (50 50 1) at a flow rate of 1.7 ml/ minute, separation and quantitation are achieved. p-Dimethyl-aminobenzaldehyde may be used as an internal standard to compensate for variations in injection technique and instrumental conditions. With a 254 nm ultraviolet absorbance detector, 0.01 ug of calcitriol may be detected (3). 

J. Liu, J. Chao, G. Jiang, Y. Cai and J. Liu, Trace analysis of sulfonylurea herbicides in water by on-line continuous flow liquid membrane extraction-C18 precolumn liquid chromatography with ultraviolet absorbance detection. J. Chromatogr.A 995 (2003) 21-28. 

Dusci LJ, Hackett P, Fellows LM, Ilett KF. 2002. Determination of olanzapine in plasma by high-performance liquid chromatography using ultraviolet absorbance detection. 

CZE = capillary zone electrophoresis EC = electrochemical detector GC = gas chromatography HCD = Hall conductivity detector HPLC = high performance liquid chromatography IDMS = isotope dilution mass spectrometry MS = mass spectrometry RSD = relative standard deviation SEE = supercritical fluid extraction SPE = solid phase extraction UV = ultraviolet absorbance detection... 

The separation and estimation of diloxanide furoate and metronidazole in solid dosage forms was reported by Bhoir et al., using packed column supercritical fluid chromatography [38], A JASCO Cig colunm (10 pm particle size, 25 cm x 4 mm) was used at 40°C, with an injection volume of 20 pL. The mobile phase consisted of 26% methanol in CO2 (flow rate of 2 mL/min), and operated at a pressure of 17.6 MPa. When detected on the basis of its ultraviolet absorbance at 230 nm, the retention time for the drug was 1.6 minutes. The linear region of the calibration graph was reported to be 20-70 pg/mL. 

Queiroz, E.F. et al., On-line identification of the antifungal constituents of Erythrina vogelii by liquid chromatography with tandem mass spectrometry, ultraviolet absorbance detection and nuclear magnetic resonance spectrometry combined with liquid chromatographic micro-fractionation, J. Chromatogr. A, 972, 123, 2002. 

Wolfender, J.-L., Ndjoko, K., and Hostettmann, K., Liquid chromatography with ultraviolet absorbance-mass spectrometric detection and with nuclear magnetic resonance spectrometry a powerful combination for the on-line structural investigation of plant metabolites, J. Chromatogr. A, 1000, 437, 2003. 

Figure 0-4 Principle of liquid chromatography, (a) Chromatography apparatus with an ultraviolet absorbance monitor to detect analytes at the column outlet. (fc>) Separation of caffeine and theobromine by chromatography. Caffeine is more soluble than theobromine in the hydrocarbon layer on the particles in the column. Therefore, caffeine is retained more strongly and moves through the column more slowly than theobromine.

Oddly, one area in which GLC is used for separation of amino acid derivatives, appears to have great potential for applications of liquid chromatography. The phenylhydantoins produced in sequence determination have ultraviolet absorbance and are efficiently separable by high-performance liquid chromatography (64). Their GLC separations are less than optimum and it is likely that new developments in this area will include liquid chromatographic separations. 

BH Reitsma, ES Yeung. Optical activity and ultraviolet absorbance detection of dansyl L-amino acids separated by gradient liquid chromatography. Anal Chem 59 1059-1061, 1987. 

Y.-F. Norio, F. Rie, T. Takenori, T. Tomonori, Determination of donepezil, an acetylcholinesterase inhibitor, in human plasma by high-performance liquid chromatography with ultraviolet absorbance detection, J. Chromatogr. B 768 (2002) 261-265. 

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