Principal peak

Reliable quantification is based on peak-search software that combines peak location, peak identification, and element deduction. Element deduction means that, for unambiguous detection, at least two of the principal peaks must be detected for each analyte of interest. In trace analysis, only the strongest peaks can be detected and special attention must be paid to interfering satellites and spurious peaks. 

Ix is the background-corrected net intensity of the principal peak of analyte X, Kx a proportionality factor for the absolute sensitivity of the standard reference, e. g. an Ni plate, and c the concentration of X. Multielement analyses are based on known relative sensitivities S ... 

The measured 5 values and estimated intensities, averaged for sixteen photographs, given in Table I lead to the radial distribution curve shown in Fig. 1, with principal peaks at 1.22, 2.34, and 3.33 A. These correspond closely with C-N = 1.47 A. (the sum of the single-bond covalent radii), N-N = 1.24 and 1.10 A., and the C-N-N angle = 120°, the peak at 1.22 A. representing the... 

The dependence of Mp" on sample size for the ethanol-soluble fraction is sumnarized by the solid lines in Figure 7. For both column sets, the apparent MW of the principal peak increases by nearly an order of magnitude as the mass of the injected sample is increased from one to four mg. In contrast, the ethanol-insoluble fraction exhibits a rather narrow chromatogram... 

Another application is to the study of the Auger states in which a further electron ionization of attachment may occur, leaving the system with holes in more than one shell. Such states were considered in some detail by Firsht and McWeeny [9] for free atoms here we have made a preliminary applieation to the nitrogen moleeule. The initial aim is simply to identify and assign the principal peaks and satellites in the Auger spectrum of gaseous N2. 

The infrared absorption spectrum of miconazole nitrate was obtained in a KBr pellet using a Perkin-Elmer infrared spectrophotometer. The IR spectrum is shown in Fig. 4, where the principal peaks were observed at 3140, 3070, 2995, 2920, 1566, 1525, 1445, 1385, 1310, 1070, and 710 cm-1. Assignments for the major infrared absorption band are provided in Table 2. Clarke reported principal peaks at 1085, 1319, 827, 1302, 1038, and 812 cm-1 (miconazole nitrate, KBr disc) [2]. 

The mass spectrum of miconazole nitrate was obtained using a Shimadzu PQ-5000 mass spectrometer. The parent ion was collided with helium as the carrier gas. Figure 15 shows the detailed mass fragmentation pattern and Table 5 shows the mass fragmentation pattern of the drug substance. Clarke reported the presence of the following principal peaks at mlz = 159, 161, 81, 335, 333, 163, 337, and 205 [2],... 

Adjust the sensitivity of the system so that the height of the principal peak in the chromatogram obtained with 10 pL of reference solution (b) is not less than 50% of the full scale of the recorder. 

Test 2. In the Assay, the principal peak in the chromatogram obtained with solution (1) has the same retention time as the principal peak in the chromatogram obtained with solution (2). 

The infrared absorption spectrum of niclosamide is shown in Fig. 4. It was obtained in a KBr disc using a Unicam SP200 infrared spectrophotometer. The principal peaks were noted at 1210, 1340, 1410, 1530, 1565, 1645, 3030, and 3270 cm-1. 

The infrared (IR) absorption spectrum of primaquine diphosphate was obtained as KBr disc using a Perkin-Elmer infrared spectrometer. The infrared spectrum is shown in Fig. 4 and the principal peaks are at 2946, 1612, 1469, 1430, 1384, 1200, 1050, 956, 815, and 760 cm-1. The assignments of the infrared absorption bands of primaquine diphosphate are shown in Table 2. Clarke reported the following principal peaks at 1611, 1595, 815, 1230, 1572, and 1170 cm-1 (KBr disk) [2],... 

The procedure is to inject 1.0 pL of each solution. The test is not valid unless, in the chromatogram obtained with reference solution, the resolution between the peaks corresponding to 2-(l-methylethyl) pentanoic acid and valproic acid is at least 2.0. In the chromatogram obtained with the test solution the sum of the areas of the peaks, apart form the principal peak, is not greater than three times the area of the peak due to the internal standard (3.0%) none of the peaks, apart from the principal peak, has an area greater than that of the peak due to the internal standard (0.1%). Disregard any peak with an area less than 0.1 times that of the peak due to the internal standard. 

Observations The assay is not valid unless the chromatogram obtained with solution (4) shows two principal peaks with a signal-to-noise ratio of at least 5. 

Column Temp. 170 °C. Inlet- principal peak obted. 

II Soln. (3) six times The relative standard deviation of the area of the principal peak is at most 2%. 

Equilibrate the column with 1 M acetic acid. Apply the cold solution to the top of the column using 0.4 ml per cm2 of column cross-sectional area. The sum of the areas of any peaks eluted before the principal peak is not greater than 5.0% of the sum of the areas of all the peaks in the chromatogram. 

Inject 5 0 pi of each solution. Adjust the sensitivity of the detector so that the height of the principal peak in the chromatogram obtained with solution (2) is 50-70% of full-scale deflection. In the chromatogram obtained with solution (1) the sum of the area of any peak eluting before the principal peak is not greater than the area of the principal peak in the chromatogram obtained with solution (2) (1.0%). 

Figure 6 depicts the relationship between the specific enthalpy of denaturation measured for CBH I at each of the pH values used in this study, and the of the principal peak at that pH. The strai t line represents a least>squares best fit to the four experimental data points and the empirically derived intersection point (Reference 2, see Discussion) in the upper right comer. All the values determined in the absence of cellobiose, both those at pH values at which the denaturation exhibits a substantial degree of overall reversibility, and those at which the overall process is completefy irreversible, are in reasonably good agreement with the linear relationship. 

TPD of Cu-Al-MCM-41 (after NO adsorption under 0.8% NO in He) was eondueted (Table 14). NO and NO2 are the species detected coming off the surface as the temperature of the catalyst is increased. Two features were observed in the NO desorption profile a principal peak at 149 °C and a second NO desorption feature at higher temperature (440 °C). This indicates that there are at least two types of NO adsorption sites available. The presence of two types of adsorbed NO species over Cu catalysts has been reported earlier in the literature[45]. These have been proposed to be the desorption of NO from Cu ions and nitrate (NO3 ), nitrite (NO2 ) or N02 adsorbed species, respectively. Assuming the sensitivity factors of the peaks at low and high temperature are equivalent, the areas can be used to estimate the normalized desorption of NO. As listed in Table 14, the amount of NO desorbed at low temperature is close to the total amoimt of desorbed NO. This feature indicates that copper is mainly as isolated Cu in the catalyst. During NO desorption, a small amoimt of NO2 (8.2 pmol/g) desorbed at 80 °C. 

Spectra of the oxides of cobalt CoO and C08O4 are shown in Fig. 14. Locations of the principal peak, at 18 and 24 ev., respectively, correlate with the valences. The extension of the fine structure throughout the 200 ev. range studied is in line with the simple crystal structures of these oxides. 

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