Reference analytical approaches

The design or evaluation for global structural damage may be performed by one of three methods energy balance, force-time history analysis or missile-target interaction analysis. 

In all cases, sensitivity studies should be performed to determine the range of consequences and the most sensitive parameters. In addition, computer codes for non-linear analysis should be validated and verified for analysis of the specific problems identified herein. 

The postulated aircraft crash should be analysed to determine its effects and the steps necessary to limit their consequences to an acceptable level. The evaluation for an aircraft crash should in general consider  

The global evaluation should include analyses of the potential for significant structural damage due to excessive deformations or displacements, which prohibit the structure from performing its function or cause the collapse or 

The impact load is generally assumed to act perpendicularly to the surface of the external structure, which can be directly impacted. A global analysis should be performed to find the displacements in different points of the buildings and to calculate the internal forces in the members not directly impacted. The representation of the impact area and its vicinity is usually done as a substructure of the global model. 

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Read a recent article from the column Analytical Approach, published in Analytical Chemistry, or an article assigned by your instructor, and write an essay summarizing the nature of the problem and how it was solved. As a guide, refer back to Figure 1.3 for one model of the analytical approach. 

AOAC Method 985.29for TDF. This AO AC method (3), referred to as the method of Prosky and co-workers (4), was cited in the Nutritional Labeling and Education Act of 1990 as the general analytical approach for food labeling of dietary fiber content. The method has undergone several modifications for IDE and for the primary fractions, SDE and IDE. 

The bifurcation of the second kind was established by Poincar6, but the bifurcation of the first kind was established more recently (1937) by A. Andronov.4 For further discussion, see this reference, or reference 6. The direct analytical approach to the theory of bifurcation is very difficult, and the only known case in which it could be carried through is that of Andronov. 

BCR Analytical Approach for the Certification of PAHs in Natural Matrix CRMs Prior to the certification analyses for the CRM, each participating laboratory has to prepare standard solutions of the analytes to be determined from certified reference compounds (purity >99.0 %) to calibrate their instruments for response and response linearity (multiple point calibration), detection limit, and reproducibility. In the case of PAH measurements, reference compounds of certified purity are used as internal standards, which are not present at a detectable concentration in the matrix to be analyzed (e.g. indeno[i,2,3-cd]fluoranthene (CRM 267), 5-methylchrysene (CRM 081R), benzo[f ]chry-sene (CRM 046), picene (CRM 168), and/or phenanthrene-dio). 

Ihnat M (1992) Selection and preparation of relevant reference materials for agricultural purposes. In Rossbach M, Schladot JD, Ostapczuk P, eds. Specimen Banking — Environmental Monitoring and Modem Analytical Approaches, pp 57-73. Springer, Berlin. 

In addition to the semiquantitative approach, more quantitative analytical approaches have been reported. For example, in the fast motion regime (t 10 11—10 9 s at X-band), one can compute the nitroxide rotational correlation time based on the measured line-widths and amplitudes (Marsh, 1981 Qin et al., 2001 Xi et al., 2008). Furthermore, it is possible to simulate a nitroxide spectrum based on quantum mechanics and specific motional models (Columbus et al., 2001 Grant et al., 2009 Hustedt et al., 1993 Liang et al., 2000 Qin et al., 2006 Schneider and Freed, 1989). The details of these advanced analysis techniques are not discussed here, interested readers are instead referred to a recent review (Sowa and Qin, 2008) and the relevant literatures. 

A reference method is an analytical method with thoroughly documented accuracy, precision and low susceptibility to interferences. The accuracy and precision shall be demonstrated by direct comparison with the definitive method and primary reference material or, where not available, with other well-characterized and documented analytical approaches) (Boutwell, 1977). As long as accuracy and imprecision are within the limits, each technique or method is acceptable as a reference method. However, for reference methods one always looks for a method easily applicable in the laboratory. Therefore, the expensive instrumentation and the relatively low sample capacity make IDMS suitable as a definitive method rather than as a reference method. For some applications, however, IDMS is the method of choice, allowing a more specific detection than the existing methods in the laboratory. 

The suitability of the two above approaches has to be tested by comparison with the reference analytical ones. Keep in mind that, up to now, the direct and indirect damping parameters are only adjustable, so what is required is only the ability for these approaches to fit the most exact theoretical SDs. 

E. Coni, A. Stacchini, S. Caroli, P. Falconieri, Analytical approach to obtaining reference values for minor and trace elements in human milk, J. Anal. Atom. Spectrom., 5 (1990), 581-586. 

The analytical approach applied in the PoweU et at. (2005) study represents a major advancement in our current study of the chemical structure of DOM. SDS-PAGE remains one of the few methods that wiU allow separation and purification of intact dissolved proteins proteomics, as applied by PoweU et at. (2005), is now routinely applied in the biochemical and biomedical fields but is rarely applied in the environmental sciences. A major advantage of these mass spectrometry based techniques (i.e., proteomics) is the relatively smaU quantity of material required for the analysis this opens up the possibility for analyzing peptides and proteins in total DOM with little or no pre-concentration. However, the presence of salts stUl needs to be minimized before effective mass spectra can be generated. A recent review by Mopper et at. (2007) highlights the application of high-resolution analytical techniques to study marine DOM composition, and we refer the reader to this review for a more comprehensive discussion of recent analytical advances. 

A comprehensive semi-empirical description of reversed-phase HPLC systems, for predicting the relative retention and selectivity within a series of analytes, has been developed by Jandera and co-workers [72,73]. The approach consists of determining the interaction indices and the structural lipophilic and polar indices. A suitable set of standard reference analytes is necessaiy to calibrate the retention (or selectivity) scale. 

The study of protein structure, function, quantity, and interactions during maturation and progression of disease is referred to as proteomics. Analytical approaches that use a combination of two-dimensional (2-D) gel electrophoresis for protein separation and MS analysis for protein identification followed by database searches is a widely practiced proteomics strategy.The tryptic peptides extracted from gels are analyzed by MALDI-TOF MS and microcolunm or capillary LC tandem mass spectrometry (MS/MS) techniques. Typically, the MALDI-TOF MS techniques are used to quickly identify peptide fragments and confirm the presence of known proteins. Nano-scale capillary LC/MS/MS techniques (using 50-100 pm diameter columns, operating at flow rates of 20-500 nL/min) are... 

The reference analytical methods for anions in wines and byproducts are summarized in Table 8.3. They use titrimetric, gravimetric approaches or selective ion electrodes, but today the most performed and extensively used approach for quality control analysis in oenology is ion chromatography. 

Figure 55-2 Multi-analyte approach to the prenatal diagnosis of methylmalonic acidemia (cb/C complementation group) by metabolite analysis in ceil-free supernatant of amniotic fluid collected at 16 weeks of gestational age. The symbol marks internal standards. A, Determination of total homocysteine by LC-MS/MS (selected reaction monitoring, SRM, transition m/z 136 to m/z 90 and m/z 140 to m/z 94 for the d -labeled internal standard). The concentration of total homocysteine was l5.7pmol/L (0.7 to 2.0pmol/L). B, Determination of methylmalonic acid by LC-MS/MS (SRM, transition m/z 231 to m/z 119 and m/z 234 to m/z 122 for the d3-labeled internal standard). The concentration of methylmalonic acid was 8.7pmol/L, the reference interval for 16 to 19 weeks of gestational age is 0.2 to 0.7)j,mol/L. C, Determination of propionylcarnitine by LC-MS/MS (parent of m/z 85 scan, the [M+H] ion of C3 is m/z 274, m/z 277 for the interna standard). The concentration was 5.6pmol/L (i.5 to l.8pmoi/L),the C3/C4 ratio was 6.9 (0.9 to 2.6).

The analytical approach to follow is a modification of the United States Pharmacopoeia method. The technique involves titrating a solution of aspirin with standard lead perchlorate solution in the presence of a Pb-ISE and reference electrode couple. Because of the PbS04 formed has a shght but significant solubility in water, the titration is carried out a solution of 37 mL acetone and 3 mL water. This solution lowers the solubility of PbS04 critically. The following solutions are required ... 

First studies combining gas chromatography and mass spectrometry in order to determine variations in the stable carbon isotope composition of organic compounds were reported in 1976 and 1978 (Sano et al. 1976 Matthwes and Hayes 1978). Matthews and Hayes referred to their analytical approach as isotope ratio monitoring mass spectrometry (irmMS) and approx. 10 years later this technique was commercially implemented. Subsequently the GC/irmMS technique and the... 

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