Diode array detection coupled

Hvattum, E., Determination of phenolic compounds in rose hip (Rosa canina) using liquid chromatography coupled to electrospray ionisation tandem mass spectrometry and diode-array detection, Rapid Commun. Mass Spectrom., 16, 655, 2002. 

Five synthetic and five natural colorants were identified and quantified in lyo-philized dairy products and fatty foods using an automatic method based on solid phase extraction using a stationary phase followed by RP-HPLC C,g columns for the sequential retention of colorants and diode array detection. Lyophilization of the samples coupled with the separation procedure provided clean extracts despite the complexity of the food matrices and preserved the sample for at least 2 months without changes in colorant concentrations. The detection limits achieved for the colorants were found in a wide range from 0.03 to 75 pg/g of the lyophilized sample, according to the limits established by the European Union. ... 

The most commonly used method for the identification of carotenoids is high-pressure liquid chromatography (HPFC) combined with the UV-Vis absorption detection. The introduction of diode array detection enabled parallel collection of pigment spectra, which greatly aids the quantification and localization of unknown compounds. Coupling HPFC with the mass-spectrometer significantly... 

A. Plum, G. Braun and A. Rehorek, Process monitoring of anaerobic azo dye degradation by high-performance hquid chromatography-diode array detection continuously coupled to membrane filtration sampling modules. J. ChmmatogrA, 987 (2003) 395-402. 

With the introduction of diode-array technology in the 1980s, a further dimension is now possible because coupled LC-UV with diode array detection (DAD) allows the chromatographic eluent to be scanned for UV-visible spectral data, which are stored and can later be compared with a library for peak identification. This increases the power of HPLC analysis... 

Santos-Buelga, C., Garcia-Viguera, C., and Tomas-Barberan, F.A., On-line identification of flavonoids by HPLC coupled to diode array detection, in Methods in Polyphenol Analysis, Santos-Buelga, C. and Williamson, G., Eds., Royal Society of Chemistry, Cambridge, Chap. 5, 2003. 

M. F. Pimentel, B. De Narros Neto, M. C. Ugulino de Araujo and C. Pasquini, Simultaneous multielemental determination using a low-resolution inductively coupled plasma spectrometer/diode array detection system, Spectrochim. Acta, Part B, 52(14), 1997, 2151-2161. 

Pesticide analysis was done by using a Hewlett Packard-1050 HPLC coupled with fluorescence detection and diode-array detection. The system for obtaining supercritical conditions was an SFE Module produced by Hewlett-Packard, with a specification shown in Table 9.6-8. 

The development of online sample procedures is critically important, for with them sensitivity increases, losses are prevented, and automation is made easy, as is demonstrated by the development of the system for automated measurement of organic micropollutants in surface water (SAMOS) LC and SAMOS GC (45,46,53,54). The SAMOS LC is based on SPE sample preparation, column LC, and diode array detection (53). Moreover, all types of MS detectors for HPLC can be coupled to the SAMOS. 

Most anthocyanin analysis today is carried out using reverse-phase HPLC, often coupled with diode array detection, as this offers the best approach to assess these compounds. The use of reverse-phase HPLC means that predictions can be made about die elution order of compounds from the column, which is based on their polarity and makes the interpretation of the anthocyanin profiles easier. A couple of useful chapters that discuss the analysis of anthocyanin pigments more fully are those of Lea (1988) and Wrolstad et al. (1995). Both of these describe more fully the types of methods used and give examples of profiles found in different fruit types. The method used by Wrolstad et al., is similar to the procedure that is routinely used at RSSL for this type of analysis. 

Irace-Guigand, S., JJ. Aaron, P. Scribe, et al. 2004. A comparison of the environmental impact of pesticide multiresidues and their occurrence in river waters surveyed by liquid chromatography coupled in tandem with UV diode array detection and mass spectrometry. Chemosphere 55 973-981. 

As an example, consider a chromatogram in which a number of compounds are detected with different elution times, at the same time as a their spectra (such as UV or mass spectra) are recorded. Coupled chromatography, such as high-performance chromatography-diode array detection (HPLC-DAD) or liquid chromatography-mass spectrometry (LC-MS), is increasingly common in modern laboratories, and represents a rich source of multivariate data. These data can be represented as a matrix as in Figure 4.3. 

Ramm, M. et al. Rapid analysis of nucleotide-activated sugars by high-performance liquid chromatography coupled with diode-array detection, electrospray ionization mass spectrometry and nuclear magnetic resonance. J. Chromatogr. A. 2004, 1034,139-148. 

Plum, A. and Rehorek, A. (2005) Strategies for continuous on-line high performance liquid chromatography coupled with diode array detection and electrospray tandem mass spectrometry for process monitoring of sulfonated azo dyes and their intermediates in anaerobic-aerobic bioreactors. J Chrom A, 1084 (1-2), 119-133. 

Bernal, J. L., Jimenez, J. J., Rivera, J. M., Toribio, L., and del Nozal, M. J., Online solid-phase extraction coupled to supercritical fiuid chromatography with diode array detection for the determination of pesticides in water, J. Chromatogr. A, 754, 145-157, 1996. 

Important applications of Af-PLS are in the area of multivariate calibrations for excitation/emission fluorescence spectrometry, for hyphenated analytical methods, such as HPLC/diode array detection and GC/MS, or for multidimensional separation techniques with or without coupling to spectroscopy. 

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