Reversed-phase high performance simultaneous analysis

MC Garcia, ML Marina, M Torre. Simultaneous separation of soya bean and animal whey proteins by reversed-phase high-performance liquid chromatography. Quantitative analysis in edible samples. Anal Chem 69 2217-2220, 1997. 

A paired-ion, reversed-phase high-performance liquid chromatographic method was developed for the simultaneous determination of sweeteners (dulcin, saccharin-Na, and acesulfame-K), preservatives (sodium dehydroacetate, SA, salicyclic acid, BA, succinic acid, methyl-para-hydroxybenzoic acid, ethyl-para-hydroxybenzoic acid, n-propyl-para-hydroxybenzoic acid, n-butyl-para-hydroxybenzoic acid, and isobutyl-para-hydroxybenzoic acid), and antioxidants (3-tertiary-butyl-4-hydroxyanisole and tertiary-butyl-hydroquinone). A mobile phase of acetonitrile-50 ml aqueous tr-hydroxyisobutyric acid solution (pH 4.5) (2.2 3.4 or 2.4 3.6, v/v) containing 2.5 mM hexadecyltrimethylammonium bromide and a Clg column with a flow rate of 1.0 ml/min and detection at 233 nm were used. This method was found to be very reproducible detection limits ranged from 0.15 to 3.00 p,g. The retention factor (k) of each additive could be affected by the concentrations of hexadecyltrimethylammonium bromide and a-hydroxyisobu-tyric acid and the pH and ratio of mobile phase. The presence of additives in dried roast beef and sugared fruit was determined. The method is suitable for routine analysis of additives in food samples (81). 

Fliniaux, M.-A. Manceau, F. Jacquin-Dubreuil, A. Simultaneous analysis of 1-hyoscyamine, 1-scopolamine and dl- tropic acid in plant material by reversed phase high-performance liquid chromatography. J.Chromatogr., 1993, 644, 193—197... 

Kursinszki, L., Hank, H., Laszlo, I., and Szoke, E. (2005) Simultaneous analysis of hyoscyamine, scopolamine, 6beta-hydroxyhyoscyamine and apoatropine in Solanaceous hairy roots by reversed-phase high-performance hquid chromatography. J. Chromatogr. A. 1091,32-39. 

The stationary phase may be a solid or liquid on a solid support. The mechanisms responsible for distribution between phases include surface absorption, ion exchange, relative solubilities and steric affects . High performance liquid chromatography is a useful method for quinolizidine alkaloid analysis, especially when pure standards are available". This method was recently used for alkaloid metabolite extraction and analysis . A simple reversed-phase liquid chromatographic method has been developed for the simultaneous quantitation of four anticancerous alkaloids vincristine, vinblastine, and their precursors catharanthine and vindoline using a specific HPLC column . 

A high performance liquid chromatographic procedure has been described [3] for the simultaneous determination of the fungicides sodium-A-methyldithiocarbamatc and methylisothiocyanate in surface waters and in sewage, based on their separation on a reversed phase column with a miscellar mobile phase (hexadecyltrimethylammonium bromide) in 1 1 v/v methanohwater buffered to pH6.8. Detection Limits were 70 and lpg dm 1 when the analysis was performed with an ultraviolet detector at 247nm. 

Also included in this experiment is a procedure for the analysis of direct and indirect additives in beverages and soft drinks (Sections E-G). This analysis may be substituted for the APC procedure if the instructor desires. High performance LC is a popular approach to analyzing beverages for caffeine, saccharin, benzoate, and other additives. Reverse-phase methods (1-5) like the one described in this experiment have been used to determine caffeine levels in coffee (2,3,5) tea (4), and soft drinks (1,5,6), with most methods including the simultaneous separation and analysis of saccharin and sodium benzoate, with minimal sample preparation required (6). With the... 

Barua, A.B. Olson, J.A. 1998. Reversed-phase gradient high-performance liquid chromatographic procedure for simultaneous analysis of very polar to nonpolar retinoids, carotenoids and tocopherols in animal and plant samples. J. Chromatogr. B 707 69-79. 

Hays, P.A. Lurie, l.S. Quantitative analysis of adulterants in illicit heroin samples via reversed phase HPLC. J.Liq.Chromatogr., 1991, 14, 3513—3517 [simultaneous acetaminophen, acetylcodeine, ace-tylmorphine, benzocaine, caffeine, chloroquine, diamorphine, diazepam, diphenhydramine, dipyrone, lidocaine, methaqualone, monoacetylmorphine, morphine, nicotinamide, noscapine, papaverine, phe-nacetin, phenobarbital, phenolphthalein, N-phenyl-2-naphthylamine, salicylic acid, strychnine] Shen, J. Wanwimolruk, S. Clark, C.R. Roberts, M.S. A sensitive assay for aspirin and its metabolites using reversed-phase ion-pair high-performance liquid chromatography. J.Liq.Chromatogr., 1990,13, 751-761 [simultaneous metabolites gentisic acid, salicyluric acid LOD 50 ng/mL]... 

Although the FI A technique does not include a separation procedure, the simultaneous determination of 5 -mononucleotides essentially requires a separation step before detection of these compounds. Thus, high-performance LC (HPLC) techniques were employed for the quantitation of 5 -mononucleotides. The 5 -mononucleotides were quantified not to determine flavor enrichment but as components of nutritional or clinical importance, especially in infant formulas [16]. Three main modes of LC are applied for nucleotide analysis ion-exchange chromatography, reversed-phase LC (RP-LC), and ion-pair RP-LC [16]. 

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