Evaluation peak area/height

Evaluation of chromatograms 133 ff -, optical trains 30, 39 -, peak area/height 31, 33,40 Evipan 339, 343... 

Evaluation of chromatograms la 133ff Evaluation, peak area or height la 31,33,40 -, optical trains la 30, 39 Evipan la 339,343 Excitation to fluorescence la 10,12,20,37 Explosion resulting from reagent residues la 82,253,261,315,365 Explosives lb 49,244,407-409 Exposure to vapors la 86... 

The Mossbauer parameters are derived from the peak parameters (base line parameters, peak position, peak width, and peak area/height) via the fitting process by computer evaluation of spectra in the case of the so-called model-dependent evaluation. In this case, an exact a priori knowledge about the spectrum decomposition (peak-shape function, number, and type of subspectra corresponding to the interactions assumed for each microenvironment in the model) is inevitably necessary. (Incorrectly chosen number of peaks renders the analysis itself incorrect.)... 

The height of the peak and area of the peak ai e traditionally used for calibration techniques in analytical chemistry. Peak maximum can also be evaluated by the height of a triangle formed by the tangents at the inflection points and the asymptotes to the peak branches. We propose to apply the tangent method for the maximum estimation of the overlapped peaks. 

Our calculations show that the systematic errors for the evaluation of the triangle height are lower then for the peak height and peak ar ea. It is to be noted that tangent method allows estimating of the latent peak in the overlapped signals when peak area and peak maximum determination is impossible. 

In their work on the precision of contemporary liquid chromatographic measurements, Scott and Reese (3) also evaluated the precision that could be expected from a computer measuring peak heights and peak areas. They again used twelve replicate samples and the results they obtained are shown in table 2. 

The factors chosen for study were the concentration of the ion-pairing reagent, the solution pH ( quantitative factors) and the acid chosen for pH adjustment (formic, acetic, propionic and trifluoroacetic acids) ( quahtative factor). The effect of these factors was assessed by using responses that evaluated both the HPLC (the number of theoretical plates and the retention time) and MS performance (the total peak area and peak height) for each of the four analytes studied, i.e. 1-naphthyl phosphate (1), 1-naphthalenesulfonic acid (2), 2-naphthalenesulfonic acid (3) and (l-naphthoxy)acetic acid (4). 

Molybdenum is an element for which platform atomisation does not offer an advantage. Just the opposite is the case sensitivity is very poor and memory effects are very strong. The Zeeman detection limit for wall atomisation in a pyrocoated graphite tube using 100 til of reference solution is 0.03 xl (for both peak height and peak area evaluation) [709]. 

The molybdenum concentration in the reference sample is rather high and a direct determination using the cookbook conditions [710] is very straightforward. There is no difference between peak area and peak height evaluation. In spite of 1800 °C for thermal pretreatment, a small background absorption signal is present. 

The traditional method of determining the position of an analyte spot on the plates is a visual evaluation. However, this technique is highly subjective and depends considerably on the expertise of the analytical chemist. TLC scanners, developed for exact determination not only pinpoint position but also the area, intensity and symmetry of the spot, overcome the uncertainty of the visual evaluation. Moreover, TLC scanners make possible more accurate determination of the quantity of analyte in the spot by converting spot characteristics into peak characteristics. Peak height is the distance between the peak maximum and the baseline, whereas peak area is the area of the peak between the beginning and end of the peak and the baseline. 

Have you had an opportunity to evaluate the results from peak heights versus peak area measurements ... 

If interferences are present and ion abundance ratios are not met using peaks areas, but all other qualitative identification criteria are met (RT, S/N, presence of all three ions), then die Contractor may use peak heights to evaluate the ion ratio. 

The Quantitative Evaluation of the Chromatogram Peak Area Measurements Peak Height Measurements Quantitative Analytical Methods for GC and LC Quantitative Analysis by TEC... 

The most important peak parameters are the peak area, the elution time of the centre of the peak and the peak variance. The peak area is proportional to the mass of the eluted compound and is usually used as the basis of quantitation. The elution time of the centre of gravity of the chromatographic peak is the elution (retention) time, fR, or the elution (retention) volume, Vr. of the compound. It is controlled by the distribution constant of the compound between the stationary and the mobile pha.ses and can be used for identification of the individual sample components. Finally, the peak variance, o (in time units) or a (in volume units) is a measure of peak broadening and can be used for the evaluation of the efficiency of the chromatographic column. For a truly Gaussian peak, the distance between the two inflection points (at 0.607 peak height) corresponds to 2(7. The peak width, u>, equals 4a and can be determined as the distance between the intersection points of the baseline with tangents drawn to the inflection points of the peak. 

As noted in Section 5.4.2 and discussed in detail in Chapter 10, the relative peak heights observed in Raman spectra are strong functions of instrumental variables. These variations can be corrected, but it is useful to have a standard with known intensities in order to evaluate the instrument and the correction procedure. Figure 5.17 shows raw and response-corrected spectra of cyclohexane for 785 excitation. The relative peak areas for cyclohexane vary with... 

The RATIO method table (Table I) includes provision for specifying upper and lower limits of integration for both primary and reference bands with the peak area evaluation procedure. The practical limits of the integration can be determined empirically by evaluating a set of spectra stored on microfloppy disks with varying limits set in the appropriate locations in the method table. Optimum limits can be determined from the calibration plots and related error parameters. The calibration plots shown in Figures 4 and 5 indicate that both evaluation procedures, peak height and peak area provide essentially the same level of precision for the linear least squares fit of the data. The error index and correlation coefficients listed on each table are both indicators of the relative scatter in the data from the least squares fit line. The correlation coefficient is calculated as traditionally defined in statistics. 

The first step in the quantitative evaluation of a chromatogram is the peak area determination or the measurement of quantities that are proportional to the peak area (peak height, peak area by multiplication of peak height and half width, triangulation). The various methods for determining peak areas or quantities proportional to the peak area differ with respect to... 

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