Peak area evaluation

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]. 

Theoretically, the function in Eq. 5.1-6 must be integrated between -oo and -l-oc. In practical IR spectroscopy, the integration can be carried out between i>o - 5 Ai>i/2 and zzo + 5 Ai>i/2. Here, Ai> is the halfwidth of the band. With modem equipment, the integrated intensities can be derived directly from the absorbance versus wavenumber spectrum. In general a peak area evaluation represents a summation of all absorbance values over the wavenumber range in which the band appears. Therefore the number of points in practical measurements depends on the wavenumber interval of the data and... 

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. 

Peak area evaluation is particularly useful when a large time interval is needed to obtain the analytical signal, e.g., for analytical procedures relying on chemiluminometric measurements [140] and for detectors with a large time constant. 

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. 

Data evaluation. It is, of course, necessary to correlate peak area with the amount or concentration of a particular solute in the sample. Quantitation by... 

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). 

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... 

With the multitude of transducer possibilities in terms of electrode material, electrode number, and cell design, it becomes important to be able to evaluate the performance of an LCEC system in some consistent and meaningful maimer. Two frequently confused and misused terms for evaluation of LCEC systems are sensitivity and detection limit . Sensitivity refers to the ratio of output signal to input analyte amount generally expressed for LCEC as peak current per injected equivalents (nA/neq or nA/nmol). It can also be useful to define the sensitivity in terms of peak area per injected equivalents (coulombs/neq) so that the detector conversion efficiency is obvious. Sensitivity thus refers to the slope of the calibration curve. 

The quality of the elution profiles, expressed as the accuracy of the peak areas, has been evaluated by Vandeginste et al. [11]. 

Calculating the P/S ratio from the corresponding peak area ratios or by using one point calibration method leads to erroneous interpretations [54] because the P/S ratio depends on sample dilution. An accurate quantitation of FA is thus needed to evaluate this important parameter correctly. 

To highlight and explain the quantitative chemical differences between the pitches found in the two archaeological sites, a chemometric evaluation of the GC/MS data (normalized peak areas) by means of principal component analysis (PCA) was performed. The PCA scatter plot of the first two principal components (Figure 8.6) highlights that the samples from Pisa and Fayum are almost completely separated into two clusters and that samples from Fayum form a relatively compact cluster, while the Pisa samples are... 

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 ability of a tPLC system to produce the same values of retention time and peak areas for analytes of interest is determined by evaluating the precision obtained under standardized conditions and analytical methods. The precision (reproducibility) values obtained are functions of the autosampler, cartridge, and detectors employed. Due to the parallel design of the tPLC system described in this chapter, reproducibility evaluations of retention time and peak area involved comparisons of results obtained for these parameters for consecutive runs performed in the same column and across different columns. 

FIGURE 6.16 Gradient method employed for evaluation of retention time and peak area reproducibility. Solvent A 5 95 H20 CH3CN with 0.1 HCOOH. Solvent B CH3CN with 0.085% HCOOH. 

---