Chromatographic peak integrity

Retain chromatographic peak integrity with minimal peak broadening. 

Figure 4.4 Examples of correct and incorrect chromatographic peak integration.

Integration by weighing. The chromatographic peak is carefully cut out of the chart and the paper weighed on an analytical balance. The accuracy of the method is clearly dependent upon the constancy of the thickness and moisture content of the chart paper, and it is usually preferable (unless an automatic integrator is available) to use geometrical methods. 

Chromatographic peak areas were measured by both manual and mechanical integration methods. Total analysis time was less than one hour per sample. 

A gas chromatograph coupled to a MC-ICP-MS for the precise determination of isotope ratios as part of the speciation application has been described, for example, for the elements S, Pb, Hg and Sb.2 Transient signals of sulfur isotope ratios (32S/34S) have been measured in an isotopic gas standard (PIGS 2010, IRMM) to determine SF6 using GC-MC-ICP-MS (Isoprobe, Micromass, UK) with a hexapole collision cell.42 For data evaluation of chromatographic peaks, peak integration limits were defined by the determination of a uniform isotope ratio zone inside... 

The chromatogram for mixture 1 showed several chromatographic peaks with one peak at retention time tR 3.50 (min) identified as 1,3-thiazolidine. The thiazolidine peak represented approximately 20% of the total integrated peak area. There were several other peaks which were probably formed from degradation reactions from the thiazolidine. 

Integration is a process of determining the area under a chromatographic peak for the quantitation of the analyte concentration. There are several scientifically valid techniques that may be used to integrate peaks. Modern chromatography computer software performs peak integration with a minimum of human intervention. Once an... 

Gas chromatographic analyses were performed on a Hewlett Packard Model 5880 system equipped with a thermal conductivity detector with an injector temperature of 200°C, detector temperature of 250°C and an oven temperature of 35°C. All runs were isothermal. The columns used for the separation were 20 foot AgNOj-ethylene glycol columns. Absolute retention times were 1.15 min (trans 2-pentene), A.65 min (1-pentene), and 5.81 min (cis 2-pentene). Methods of automatic peak integration that were used during the analyses were peak height, peak area, area %, and internal standard experiments. 

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