Sampling reproducibility

Figure 13-10. Diagram illustrating the three configurations of the sphere required for the efficiency measurement, (a) The sphere is empty (b) the sample is in place and ihc laser beam is directed at the wall (c) the laser beam is directed on the sample. Reproduced with permission front [I26. ...

Fig. 3.11 Conventional flasks for microdeterminations (a) air leak design (A) stopper design (c) filter paper for wrapping sample. Reproduced by permission from A. M. B. Macdonald, in Advances in Analytical Chemistry and Instrumentation, C. N. Reilly (Ed.), Vol. 4, Interscience, New York, 1965, p. 75.

Fig. 3a. P200 and P400 as a function of draw ration for the pseudo-affine deformation scheme (uniaxially oriented sample) b P20o and P400 as a function of draw ratio X for the rubber network affine deformation scheme (N = 6, uniaxially oriented sample). Reproduced from Journal of Polymer Science by permission of the publishers, John Wiley Sons Incs (C)...

Figure 4.39 Development of peak profiles during migration along the column for analytical and overload samples. (Reproduced with permission from ref. 608. Copyright Elsevier Scientific Publishing Co.)...

Figure 9 SEC Response versus retention volume for (a) RID, (b) VD, and (c) LS detector for the same sample. Reproduced from Beer et al. [70]. Copyright 1999 John Wiley Sons, Inc. Reprinted with permission of Wiley-Liss, Inc., a subsidiary of John Wiley Sons, Inc.

Fig. 1 Reported ranges of emerging contaminant concentrations in sludge samples. Reproduced...

The use of a special device that allows filtration under nitrogen, the direct introduction of sample into containers for storage during filtration and, the use of these containers as analysis cells are all improvements that minimise external sample contamination and improve between-sample reproducibility. 

Figure 1. Relationship between the flammability and metal compound level of brominated polyester resin samples. (Reproduced with permission from Ref.3 > Copyright 1989 John Wiley Sons Ltd.)...

FIGURE 1.25 Principle of operation of solid-supported liquid-liquid extraction from aqueous or plasma samples. (Reproduced with permission from Varian, Inc.)... 

Figure 2.19 Transmission electron micrograph of a K3 sol-gel sample. (Reproduced from ref. 14, with permission.)... 

Figure 5. Pt NMR lineshapes for six untreated samples. Reproduced with permission from Ref. 1. Copyright 1982, The American Physical Society.

Figure 1.11 Transmission IR spectra from Co Mo Oy (0 < x < 1) samples obtained by addition of different amount of Co304 to pure Mo03 [79]. As the Co/Mo ratio is increased from 0.25 to 1, the IR peaks due to tetrahedral Mo04 units (at 662 and 946 cm-1) grow at the expense of those associated with the Mo03 phase (at 563, 820, 863, and 993 cm-1), a trend that indicates the formation of CoMo04. This example shows how IR can be used to directly characterize solid catalyst samples. (Reproduced with permission from Elsevier.)...

Figure 1.18 Survey and expanded V 2p and Mo 3d XPS spectra form a Mo-V-Sb-Nb mixed oxide catalyst after calcination in nitrogen (a) and air (b) atmospheres [145]. The data indicate a lesser degree of oxidation in nitrogen, a result that was correlated with the promotion of reactions leading to the production of propene and acrylic acid rather than acetic acid, the main product obtained with the fully oxidized sample. (Reproduced with permission from Elsevier.)...

The conventional methods of analysis for total petroleum hydrocarbons (Chapter 7) have been used widely to investigate sites that may be contaminated with petroleum hydrocarbon products (see also EPA 418.1) for the determination of petroleum hydrocarbons. The important advantage of this method is that excellent sample reproducibility can be obtained, but the disadvantages are that... 

Gas chromatograph systems are composed of an inlet, carrier gas, a column within an oven, and a detector (O Figure 1-1). The inlet should assure that a representative sample reproducibly, and frequently automatically, reaches the column. This chapter will cover injection techniques appropriate for capillary columns. These include direct, split/splitless, programmed temperature vaporization, and cool on-column injection (Dybowski and Kaiser, 2002). 

Figure 5 GC/ITMS total ion and mass chromatograms of an ocean water sample [Reproduced from S.-A. Barshicket al., Anal. Chem.,70 (1998) 3015. Copyright 1998, with permission from the American Chemical Society].

Figure 9 LC/MS-ESI mass chromatograms of a Semtex sample [Reproduced from X. Zhao and J. Yinon, J. Chromatogr. A, 977 (2002) 59. Copyright 2002, with permission from Elsevier].

Fig. 3.2 SEC chromatograms from typical ALIS experiments. (A) UV responses from detectors positioned before and after a sampling valve show that the protein-ligand complex, eluting at 20 s, is excised from the SEC stream for transfer to RPC-MS. (B) An overlay of ten SEC chromatograms demonstrates ALIS sample-to-sample reproducibility. Reprinted from [40] with permission from Elsevier.

Fig. 7 Ellipsometric mapping of PBA/P2VP gradient brush, total thickness ( ), PtBA layer ( ), P2VP layer (A), (b) Fraction of PtBA versus the point coordinate on the sample (Reproduced with permission from [27])...

Fig. 13 Carbon K-edge partial electron yield (PEY) NEXAFS spectra collected from the CMPE-SAM (top) and OTS-SAM (bottom). The arrow marks the position of the Is tt transition for phenyl C = C, present only in the CMPE-SAM sample. (Reproduced with permission from [76])...

Figure 1. RR spectra with 406.7nm excitation for ZnOEP (0.5ii, bottom) in CH2Cil2 (50mW incident laser power) and for solutions with increasing amounts of monocation radical formed by electrolysis at 0.85V vs. SCE (15mW). Each scan was obtained with a fresh sample (Reproduced from Ref. 5. Copyright 1986 American Chemical Society.)...

FIGURE 2.20 Coomans plot of SIMCA models of three-months and six-months aged wine samples (reproduced from Parra et al., 2006a, with permission). 

Reproducibility is the precision determined under different conditions (laboratory, reagents, analysts, days, equipment) with one homogeneous sample. Reproducibility may also be established retrospectively, using data obtained from earlier release procedures. 

Figure 19.12—Karl Fischer instrument (coulometric version). Model DL-37 with an external device that includes an oven to extract water from solid samples. (Reproduced by permission of Mettler Toledo.)...

Figure 1. Sep- Pak adsorption and meth ylene chloride extraction of Dursban (see arrows) from water samples 2 and 3. (The 10X denotes the concentration factor for Dursban above the original concentration in the water samples.) (Reproduced with permission from reference 13. Copyright 1980...

We have previously studied the dynamics of normal DNA [5-8], Here we present experimental evidence that DNA damage results in specific changes to its dynamics. Two kinds of prototypical DNA damage Eire studied and compared with an equivalent undamaged sequence. An abasic sample reproduces the most common type of in vivo damage to DNA, the loss of a single base. The chain-end sample explores a more severe type of damage, the disruption of the helical structure at the severed end of a DNA chain. 

Figure 5. A denuder-filter-sorbent system for PAH sampling. (Reproduced with permission from reference 63. Copyright 1988.)...

What constitutes a significant difference between two spectra When the differences are small, the answer depends on sample preparation and sample stability as well as accuracy of concentration determination, identification of and compensation for drift in the spectrometer, correct baseline correction, absence of bubbles in the sample, reproducible cleanliness of the cuvette, and the level of general handling procedures. Ultimately, an assessment of significance depends on the experience, competence, and confidence of the operator. 

Collaboratively tested in 12 laboratories using 8 samples reproducibility CV 12-35%. 

Amperometric activity of the electrodes in thiocholine before and following exposure to solutions of pesticides was measured. Sample to sample reproducibility was found to be favourable (RSD 6.6%), as was stability with electrodes being shown to be capable of being stored for up to 2 months at —18°C. Linear detection of chlorpyrifos methyl oxon by inhibition was obtained between 1 x 10 8 and 5 x 10 8M by this approach. 

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