Analysis reproducibility

Figure 3.4 Two-dimensional separation of dimethylnaphthalenes in crude oil using a 50 m methyl (95%)/phenyl (5%) polysiloxane primary column and a 50 m methyl (50%)/phenyl (25%)/cyanopropyl (25%) polysiloxane secondary column. The top trace indicates the primary separation monitor, while the following chromatograms indicate individual heart-cut secondary analysis. Reproduced from R.G. Schafer and J. Holtkemerr, Anal. Chim. Acta. 1992, 260, 107 (20).

A systematic difference is found, supported by indirect evidence that from experience precludes any explanation other than effect observed. This case does not necessarily call for a statistical evaluation, but an example will nonetheless be provided in the elemental analysis of organic chemicals (CHN analysis) reproducibilities of 0.2 to 0.3% are routine (for a mean of 38.4 wt-% C, for example, this gives a true value within the bounds 38.0. .. 38.8 wt-% for 95% probability). It is not out of the ordinary that traces of the solvent used in the... 

Figure 4. Contributions of nearest neighbor copper and osmium backscattering atoms (circles in fields B and C, respectively) to the EXAFS (solid line) associated with the osmium Ltjj absorption edge of a silica supported osmium-copper catalyst, me circles in field A represent the combined contributions resulting from the data analysis. Reproduced with permission from Ref. 12. Copyright 1981, American Institute of Physics.

FIGURE 4.9 The autocovariance function close to the origin of a 2D separation. The maximum amplitude and the characteristic half-widths at half-heights are used in the simplified analysis. Reproduced from Marchetti et al., (2004) with permission from the American Chemical Society. 

FIGURE 4.12 Experimental 2D-PAGE map of a neuroblastoma xenograft implanted in mice. The circles indicate the spots identified by MS analysis. Reproduced from Campostrini et al. (2005) with permission from Wiley-VCH Verlag GmbH. 

The pH used in the first C18 separation dimension was rather high (pH 10), however, no peptide loses or carryover, due to on-column precipitation, were observed. Peak shape was comparable to peptide analysis at low pH. Modern stationary phases, based on hybrid silica and stable alkyl bonding chemistry, are well suited for chromatography at extreme pH without compromising column lifetime or analysis-to-analysis reproducibility (Wyndham et al., 2003). 

Figure 6.5 The /A2MS technique consists of (a) laser desorption followed by (b) laser ionisation to selectively produce ions, that are then extracted into a time-of-flight mass spectrometer for mass analysis. (Reproduced by permission of R.N. Zare, Stanford University)...

Method development procedure for calibration-curve-based analysis. (Reproduced with permission from D. 6. Mitchell and J. S. Garden, Talanta, 1982, 29, 921-929, copyright 1982,... 

Figure 9. Dark-field TEM images of Au/C and Au/MnOx/C [75], These catalysts were pretreated in 02-Fle at 200oC, tested in CO oxidation, and then collected for TEM analysis. [Reproduced by permission of Elsevier from Ma, Z. Liang, C. D. Overbury, S. El. Dai, S. J. Catal. 1001, 252, 119-126.1.

Table 6.4 Composition and notation of catalysts submitted to XPS and EXAFS/XANES analysis(Reproduced from Reference [30].)...

Fig. 3. GC-AED profiles of gas oil fractions (12). Estimated percentages from LC analysis. Reproduced from Ref. /2, with permission.

From the chromatogram of the sample under analysis, reproduced below, and the information given in the table, find the mass composition of this mixture (ignore the first peak at 0.68 min.)... 

Effect of volume fraction of SiC whiskers in composite with code 1723 matrix on critical aspect ratio, according to (O) Dow s analysis and( ) Rosen s analysis (reproduced by permission of Am. Ceram. Soc. Bull.) . 

Figure 4.18. Ion current summation chromatogram for m/z 83 + 129 + 173 from trihalo-methane analysis. (Reproduced from Ref. 51, with permission from the American Chemical Society.)...

Thus for noninteracting electrons, density functional analysis reproduces the usual Schrodinger equations, but a theory based solely on densities (a time-dependent... 

Fig. 3. A schematic view of a crossed-molecular beam apparatus used for studying the reactions of chlorine atoms with halogen molecules. The mass spectrometer detector is rotatable about the scattering centre for measuring the angular distributions of the reaction products whose recoil velocities are determined by time-of-flight analysis. (Reproduced from ref. 558 by permission of the authors and the American Institute of Physics.)...

Figure 6b. Vibration Analysis. Reproduced with permission of ISSCO.

Absorption at 650 nm was found to increase in around 1 ps in accord with the decay of the absorption at 515 nm after irradiation with a 360-nm laser pulse (fiyhm 180 fs). The absorption bands at 515 and 650 nm were assigned to S i - Sn transitions of the open-ring form (or some intermediate produced from the excited state of the open-ring form) and the closed-ring form, respectively. By taking into account the pulse duration and the time constant of formation of 1.1 ps, this kinetic analysis reproduced the decay and the rise profile. This result clearly indicates that the photocyclization of the dithienylethene took place in 1 ps. 

HPLC/APCI separation of a mixture of five benzodiazepines. A 1.2 ml min-1 CH3CN-CH30H-H20 (40 25 35 v/v) flow is used for the analysis. Reproduced (modified) from Huang E.C., Wachs T., Conboy J.J. and Henion J.D., Anal. Chem., 62, 713A, 1990, with permission. 

Statistical data on the analysis of oxide products should be based on the same criteria as for iron and steel analysis. Reproducibility limits of about 1—2rel.% are valid in the case of direct analysis with A AS. The use of the injection technique leads to reproducibilities of 2—5rel.% for high salt content and 10—20rel.% for the graphite tube technique (low salt content) used as a trace method. 

Figure 7.20. Comparison of WDS (top, using LiF and thallium acid phthalate (TAP (1010), respectively) and EDS for the analysis of a superalloy. A number of X-ray spectral lines such as Ta La, Ni Kp, and W La are hardly discernible using EDS, but readily visible using WDS analysis. Reproduced with permission from Goldstein, J. Newbury, D. Joy, D. Lyman, C. Echlin, R Lifshin, E. Sawyer, L. Michael, J. Scanning Electron Microscopy and X-Ray Microanalysis, 3rd ed., Kluwer New York. Copyright 2003 Springer Science and Business Media.

Yates has developed a rather more sensitive method of analysing the results( j but generally, particularly when the number of blocks in the experiment is not very-large, the increase in accuracy is not very great, and the earlier method of analysis reproduced here will normally suffice. 

Figure 5, Block diagram of electronics for size analysis. (Reproduced with permission from Ref. 2. Copyright 1983, Japan Association of Automatic...

Figure 13.3 Adsorption isotherms of resorcinol, catechol, and phenol on Lichrosorb RP-18 measured by FA and by system peak analysis. Reproduced with permission from S. Levin, S. Abu-Laji, S. Golshan-Shirazi, G. Guiochon, J. Chro-matogr. A, 679 (1994) 213 (Fig. 3).

Figure 10.1 General instrumentation for thermal analysis. (Reproduced with kind permission of Springer Science and Business Media from M. Brown, Introduction to Thermal Analysis, Kluwer Academic Publishers, Dordrecht. 2001 Springer Science.)...

Figure 3. Molecular weight distribution of experimental resins X0, X1 X2, and X3 determined by SEC analysis. (Reproduced with permission from ref. 7. Copyright 1988 IEEE.)...

Fig. 6. Diagram of the low-frequency apparatus for decomposition of gasoline and in situ gas chromatographic assembly for product analysis. (Reproduced from Venugopalan, M., Scott, T. W. Z. physik. Chem. Neue Folge, 108,157 (1977), by permission of the authors and the publishers, Akademische Verlagsgesellschaft)...

Figure 21.4 Micro-extraction procedures, (a) Micro-extraction using an adsorption fibre (b) Micro-extraction with a single drop of organic solvent. Advantages of this technique are ultra small volume of sample, low chemical consumption and fast analysis (reproduced courtesy of Supelco).

Figure 8.18 Report and chromatogram from an external standard analysis. (Reproduced by...

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