Chromatography software

Dionex Corporation - Manufacturers of liquid chromatography systems (IC and HPLC), chromatography software data systems, reversed-phase and ion-exchange columns, and accelerated solvent extraction systems... http //www.dionex.com. 

DryLab Chromatography Software, http //www.rheodyne.com/products/ chromatography/drylab/index.asp. 

Fig. 6.1.4 Components of the high-performance liquid chromatography (HPLC) system for oxidized pterins with column switching. The autosampler starts the chromatography software, which controls valves and pumps. Pump 3 is used only for rinsing the precolumn. Details of the three valves and their different positions are explained in Fig. 6.1.5...

Modular isocratic HPLC with ED detection HPLC pump 515 (Waters), Injector 7725i (Rheodyne), Pulsation Reduced (Portman Instruments), Coulochem Detector Model 5100A (ESA), Analytical Cell 5011 (ESA), and PC with chromatography software (SCPA). 

If LC-NMR/MS is carried out, the data obtained from the mass spectrometer is often used to identify peaks of interest. For this purpose, it is preferable that the chromatography software itself must be able to create and display chromatograms from the mass spectra. 

In order to allow selection of these peaks, the separation is monitored by an LC detector, in most cases a conventional UV detector, which displays a chromatogram of the separation. The chromatography software must allow selection of certain positions in the chromatogram for further measurement. 

An interface controlling the flow path using switching valves controlled by software. The latter also carries out peak detection and is preferably a part of the main chromatography software. 

An NMR spectrometer under the control of software which allows the automatic acquisition of spectra with solvent suppression. Communication with the chromatography software is also necessary. 

The concentrations of the individual silymarin compounds and taxifolin were determined by HPLC using a Waters system (Milford, MA) composed of an Alliance 2690 separations module and a 996 Photodiode Array detector controlled with Millennium32 chromatography software. The HPLC procedure was previously described by Wallace et al. (13). Calibration curves were prepared from standard solutions of taxifolin, silychristin and silymarin. The silybinin standard from Sigma contained two distinct peaks, which are further referred to as silybinin A (the first peak) and silybinin B (the second peak). 

By far the simplest are univariate approaches. It is important not to overcomplicate a problem if not justified by the data. Most conventional chromatography software contains methods for estimating ratios between peak intensities. If two spectra are sufficiently dissimilar then this method can work well. The measurements most diagnostic for each compound can be chosen by a number of means. For the data in Table 6.1 we... 

Standard application software, for example, COTS chromatography software, generally supplied by an instrument vendor. The correct function should be verified during and at the end of development. The user must perform acceptance testing prior to use. 

The following paragraphs describe a procedure for the verification of important chromatography software functions without injecting a sample (Figure 19.3). The concept has been described in detail elsewhere. It is very generic and can also be used to test and verify the correct functions of other software packages. 

For the most part, contemporary computer chromatography software does not provide for situations where (r l) so the analyst can only use peak height data from the program and make the corrections manually. Alternatively, the chromatogram can be processed completely manually in which case peak areas can be used. The magnitude of any error that can arise from not correcting for (r) when it is other than unity can only be accessed, if and when the actual value of (r) is determined in the manner discussed in chapter 2. Unfortunately very few instrument manufacturers provide a value for (r) and thus the... 

Applications have been reported in many areas including analysis of lipids, oils, fatty acids, polymers, asphalt, and surfactants. The advantages of this method are high throughput, low cost per sample, easy quantitation using standard chromatography software, and simple method development analogous to standard TLC. 

The first step in the evaluation process is to define and document the current system use and user requirement specifications. If the system will be changed in the foreseeable future, any resulting changes in the intended use of the system should be described as well. The definition should include a list of system functions, operational parameters and performance limits. For chromatography software required functions may include instrument control, data acquisition, peak integration through quantitation, file storage and retrieval and print-out of methods and data. If the system also includes spectrophotometric detectors, the functions for spectral evaluation should be specified as well. Table 2 lists items that should be included in the system documentation. 

Note With the computers in use today to record chromatograms, it is easy to determine the true variance of a peak. Nevertheless, the old manual approximations have established themselves and chromatography software programs go to great length to emulate the old manual procedures.)... 

Various computer-assisted chromatographic optimization methods have been developed to optimize separation selectivity It should be pointed out that most of the method development strategies, as well as many types of chromatography softwares, have been focused on... 

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