Array coulometric

NURMI T, ADLERCREUTZ H (1999) Sensitive HPEC method for profiling phytoestrogens using coulometric array detection application to plasma analysis, Analytical Biochemistry, 274, 110-17. 

GUO c, CAO G, SOFIC E and PRIOR R L (1997) High-performance liquid Chromatography coupled with coulometric array detection of electroactive components in fruits and vegetables Relationship to oxygen radical absorbance capacity, J Agric Food Chem, 45, 1787-96. 

Ferruzzi, M.G. et ah. Analysis of lycopene geometrical isomers in biological microsamples by liquid chromatography with coulometric array detection, J. Chromatogr. B Biomed. ScL Appl. 760, 289, 2001. 

Inoue, K., Murayama, S., Seshimo, F., Takeba, K., Yoshimura, Y., and Nakazawa, H. (2005). Identification of phenolic compound in manuka honey as specific superoxide anion radical scavenger using electron spin resonance (ESR) and liquid chromatography with coulometric array detection. /. Sci. Food Agric. 85, 872-878. 

Microcoulometric titration is used as the detection mode in some commercial sulfur-specific analysers. Sulfur in PP and waxes (range from 0.6 to 6 ppm S) were determined by means of an oxidative coulometric procedure [537]. The coulometric electrochemical array detector was used for determining a variety of synthetic phenolic antioxidants (PG, THBP, TBHQ, NDGA, BHA, OG, Ionox 100, BHT, DG) in food and oils [538],... 

UV detection, diode-array detector (DAD) and fluorescence have been the detection techniques used, coupled to HPLC for the analysis of OTC. UV detection is set at 355 nm [49-51], 350 nm [40], or at 353 nm [52], Using the diode array detector [49] offers advantages that the target peak can be identified by its retention time and absorption spectrum. Compared to UV detection, fluorescence detection is generally more specific and is less interfered by other compounds in the sample matrix [51]. A HPLC method with electrochemical detection has also been suggested recently. Zhao et al. [53] described HPLC with a coulometric electrode array system for the analysis of OTC, TC, CTC, DC, and methacycline (MC) in ovine milk. An amper-ometric detection coupled with HPLC was developed by Kazemifard and Moore [54] for the determination of tetracyclines in pharmaceutical formulations. 

The multichannel coulometric detection system serves as a highly sensitive tool for the characterization of antioxidant phenolic compounds because they are electroactive substances that usually oxidize at low potential. The coulometric efficiency of each element of the array allows a complete voltammetric resolution of analytes as a function of their oxidation potential. Some of the peaks may be resolved by the detector even if they coelute (Floridi and others 2003). 

Aaby K, Hvattum E and Skrede G. 2004. Analysis of flavonoids and other phenolic compounds using high-performance liquid chromatography with coulometric array detection relationship to antioxidant... 

Floridi S, Montanari L, Marconi O and Fantozzi P. 2003. Determination of free phenolic acids in wort and beer by coulometric array detection. J Agric Food Chem 51(6) 1548—1554. 

An assay for NE, E, L-DOPA, DA, 3-nitrotyrosine, m-,o-, and p-tyrosine compared an amperometric detector with a CoulArray detector. A CoulArray detector has the sensitivity of a coulometric detector applied to eight different electrodes to give an array of applied voltages. A C18 column with a mobile phase consisting of an acetate buffer (pH 4.75) and sodium citrate in methanol was used. The assay was... 

Another application utilizing the coulometric array detector is the simultaneous determination of biogenic amines, kynurenine, and indole derivatives of tryptophan. The method employed a CIS column with a phosphate-acetate mobile phase (pH 4.1) containing methanol and sodium octyl sulphonate (Vaarman et al., 2002). 

Having optimised the efficiency of a chromatographic separation the quality of the chromatography can be controlled by applying certain system suitability tests. One of these is the calculation of theoretical plates for a column and there are two other main parameters for assessing performance peak symmetry and the resolution between critical pairs of peaks. A third performance test, the peak purity parameter, can be applied where two-dimensional detectors such as diode or coulometric array or mass spectrometry detectors are being used. The reproducibility of peak retention times is also an important parameter for controlling performance. 

Achilli, G. et ak, Identification and determination of phenolic constituents in natural beverages and plant extracts by means of a coulometric electrode array system, J. Chromatogr., 632, 111, 1993. 

The detection system consisted of a coulometric electfochemical cell preceded by a diode array detector followed in series by a fluorescence detector. 

When the coulometric detector was turned on, both leuco forms were completely oxidized to their nonfluorescing chromatic forms and thus vanished from the fluorescence channel. This disappearance was balanced by the arrearance of their chromatic forms in the diode array channel. The confirmation of malachite green, gentian violet, and tlieir leuco analogs in catfish and trout tissue could be based, therefore, on the correct retention times, the observation of the natural fluorescence of the leuco forms when the coulometric detector was turned off, the absence of the leuco form peaks in the 588 nm channel when the coulometric detector was off, the disappearance of the fluorescence of the leuco forms when the coulometric detector was on, the appearance of peaks of parent drugs formed by oxidation of the leuco forms in tlie. S88-nm diode array channel, and the correct ultraviolet-visible spectra maxima for all four peaks. 

Ferruzzi, M.G., Sander L.C., Rock C.L., and Schwartz S.J. 1998. Carotenoid determination in biological microsamples using liquid chromatography with a coulometric electrochemical array detector. Anal. Biochem. 256 74-81. 

Gamache, P.H., McCabe, D.R., Parevez, H., Parvez, S., and Acworth, I.N. 1997. The measurement of markers of oxidative damage, antioxidants and related compounds using HPLC and coulometric array analysis. In Columetric Electrode Array Detectors for HPCL (l.N. Acworth, M. Naoi, S. Parvez, and H. Parvez, eds.) pp. 91-119. VSP Publications, Zeist, The Netherlands. 

An HPLC method using progressive electrochemical detection of SPA was described by McCabe and Acworth (128). Samples were mixed with hexane, and SPA were extracted with acetonitrile. An HPLC analysis of the extracts was performed, without an evaporation step, on a high-pressure Coul Array system in which analytes were detected on two coulometric array-cell modules, each containing four electrochemical sensors attached in series after the column. Analytes were separated on a Supelcosil LC-18, 5-/tm column using gradient elution and detected at potentials of —50, 0, 70, 250, 375, 500, 675, and 825 mV. To remove oxidative impurities to be coeluted with BHT, a guard cell with applied potential of 900 mV was also placed in the system. 

Many published articles on HPLC-ECD refer to the use of one of three voltammetric detectors (amperometric, coulometric, or polarographic). More detailed information on principles and techniques of various electrochemical detection modes can be obtained from the recent book, Coulometric Electrode Array Detectors for HPLC (34). There are also two electrode array detectors, the coulometric electrode array system and the CoulArray detector, currently available. Both detectors offer the qualitative data of PDA and the extreme sensitivity of ECD (34). The... 

P Gamache, E Ryan, IN Acworth. Analysis of phenolic and flavonoid compounds in juice beverages using high-performance liquid chromatography with coulometric array detection. J Chromatogr 635 143-150, 1993. 

IN Acworth, M Naoi, H Parvez, S Parvez. Coulometric Electrode Array Detectors for HPLC. Utrecht, The Netherlands VSP, 1997, pp 1-382. 

PH Gamache, IN Acworth, ML Lynch, WR Matson. Coulometric array detection for HPLC in the analysis of juice products. In S Nagy, RL Wade, eds. Methods to Detect Adulteration of Fruit Juice Beverages. Auburndale, FL Agscience, 1995, pp 120-144. 

Achilli, G., Cellerino, G. P., Melzi d Eril, G. V., and Tagliaro, F. (1996). Determination of illicit drugs and related substances by high-performance liquid chromatography with an electrochemical coulometric-array detector. J. Chromatogr. A 729 273-277. 

Cheng, M. H., Lipsey, A. I., Lee, J., and Gamache, P. H. (1991). Automated analysis of urinary VMA, HVA, and 5-HIAA by gradient HPLC using an array of eight coulometric electrochemical detectors. Lab. Robot. Auto. 4 297-303. 

Gamache, P. H., Kingery, M. L., and Acworth, I. N. (1993). Urinary metanephrine and norme-tanephrine determined without extraction by using hquid chromatography and coulometric array detection. Clin. Chem. 39 1825-1830. 

Hill, B. A., Kleiner, H. E., Ryan, E. A., Dulik, D. M., Monks, T. J., and Lau, S. S. (1993). Identification of multi-S-substituted conjugates of hydroquinone by HPLC-coulometric electrode array analysis and mass spectroscopy. Chem. Res. Toxicol. 6 459-469. 

Roy, S., Venojarvi, M., Khanna, S., and Sen, C. K. (2002). Simultaneous detection of tocopherols and tocotrienols in biological samples using HPLC-coulometric electrode array. Methods Enzymol. 352 326-332. 

Zhang, X. Z., Gan, Y. R., and Zhao, F. N. (2004). Determination of salbutamol in human plasma and urine by high-performance liquid chromatography with a coulometric electrode array system. J. Chromatogr. Sci. 42 263-267. 

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