Case studies contaminant analysis

In this section, two examples of recent application of MIPs to contaminant analysis in the food industry, developed as part of the EC project FAIR CT96-1219, are considered. 

The details regarding preparation of clenbuterol imprinted polymers, HPLC columns and detection have been described previously (Crescenzi et al., 1998). A typical chromatogram showing the resolution of clenbuterol and timolol from a mixture at pH values 2.0 and 3.4 is shown in Fig. 4.2. In terms of the selectivity of the stationary phase, expressed as separation factor a, the values at pH 2.0 and pH 3.4 were 3.1 and 14.4, respectively. For control particles, the a value was 1. 

The extracted samples (in mobile phase acetonitrile 0.001M phosphate buffer pH 3.4, 70 30) were injected (20 (A per sample, 1 ml/min flow rate) onto the clenbuterol-MIP and blank polymer packed HPLC columns. The bound fraction was eluted in the mobile phase and the elution profile monitored at 208-300 nm. 

2 MIP-based extraction of /3-lactam antibiotics from milk 

The details regarding preparation of oxacillin imprinted polymers, HPLC columns and detection have been described previously (Briiggemann et al., 

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From the case studies reported in this chapter, it has been shown that a systematic approach to failure analysis and contamination issues can be applied to a broad and diverse range of industrial problems. The use of techniques such as SEM, NMR, and FTIR can often provide information relevant to the cause of... 

This topic has been mentioned in Section V, Failure, Defect and Contaminant Analysis, in Chapter 15, where a number of typical practical problem invetsigations were presented. Obviously the potential list of examples exhibiting different characteristics and requiring a different type of analysis is lengthy. When the sample is heterogeneous, e.g., a polymer blend or a composite, the study of the surface of a failed piece of material may reveal whether the problem is the interface of the components or that failure occurred within one of these. In particular in the case of crazing or necking orientation may have been induced, the way this can be analysed is discussed in Chapter 8. 

Case Study. Such a situation was found to occur in the duct network shown in Fig. 21 and installed to extract iron oxide dust at various points along a cold strip processing line. The stated problems were insufficient suction at the hoods, buildup of contaminant in the hoods and along the processing line (causing cleanup problems due to eventual mixing with hydraulic fluid, lubricant, water, etc.). Analysis of the system found the following ... 

Senz G, Pingitore N. 1991. Characterization of hydrocarbon contaminated areas by multivariate statistical analysis Case studies. Environ Monit Assess 17(2-3) 281-302. 

The Pellston workshop in February 2002, which produced this book, aimed to develop guidance and increased consensus on the use of uncertainty analysis methods in ecological risk assessment. The workshop focused on pesticides, and used case studies on pesticides, because of the urgent need created by the rapid move to using probabilistic methods in pesticide risk assessment. However, it was anticipated that the conclusions would also be highly relevant to other stressors, especially other contaminants. 

Lindstrom AB, Highsmith VR, Buckley TJ, et al. 1994. Gasoline-contaminated ground water as a source of residential benzene exposure A case study. Journal of Exposure Analysis and Environmental Epidemiology 4(2) 183-195. 

Barber, C., Briegel, D. J., Power, T. R.,and Hosking, J. K.(1992). Pollution of groundwater by organic compounds leached from domestic solid wastes a case study from Morley, Western Australia. In Groundwater Contamination and Analysis at Hazardous Waste Sites, ed. Lesage, S., and Jackson, R. E., Marcel Dekker, New York, 357-380. 

Case Study Quick Turnaround Analysis of PAHs by HPLC in Multimedia Samples This case study describes quick turnaround HPLC methodologies for the analysis of 16 priority pollutant PAHs in multimedia samples such as contaminated soil, air particulate matter, used engine oil, and... 

Walentowicz, R. Falco, J.W. "Stochastic Processes Applied to Risk Analysis of TCDD Contaminated Soil A Case Study", Unpublished Report, 1984 Exposure Assessment Group, ORD,... 

Topics presented indude analysis of poKutants, soil physics, and environmental fate remediation techniques health effects regulations and case studies. A special section is included on petroleum contamination in ground water and soils. 

As was explained in the hegirming of this chapter, the background to this study was partly that an analysis of socially efficient contamination levels could not be undertaken due to lack of information on benefits. This case study has now provided some benefit estimates. However, the conclusions drawn above imply that they have to be used with great care, since it is not entirely clear for what benefits they are valid. 

In summary, an analysis of these field demonstrations reveals that a detailed study of contaminated sites is necessary for the successful application of the technology. Since no sites are alike, a case-to-case study is relevant in each case. Pretreatment of soil is also to be undertaken if necessary. Methods should be further developed to be more specific and selective as the success of the field remediation is largely operationally defined. 

Hackley, B. and A. Katz-Jacobson. (2003) Lead poisoning in pregnancy A case study with implications for midwives. Journal of Midwifery and Women s Health 48(1) 30-38 Holstege, C.P., J.D. Ferguson, C.E. Wolf, A.B. Baer and A. PokUs. (2004) Analysis of moonshine for contaminants. J. Toxicol. 42(5) 597-601... 

The use of environmental case studies, related to plastics waste, enables analysis of the extent to which contamination may adversely impact property value through the effect previously referred to and defined as environmental stigma [8]. 

Papesch, W, Horacek, M. (2009) Eorensic appheations of stable isotope analysis case studies of the origins of water in mislabeUed beer and contaminated diesel fuel. Sci. Justice, 49,138-141. 

A number of methods can be employed to monitor remedial progress, including the use of monitoring wells, groundwater analysis, and effluent vapor analysis. Selected case studies are summarized in Table 14.1 and in this section to provide information on expected contaminant removal using air sparging systems. 

Compton et al. [18] have worded some (fairly obvious) conditions for the feasibility of a quantitative method (Table 6.4). In developing quantitative methods for polymer/additive analysis Murphy s Law always applies, as also apparent from some of the following Case Studies. Quantitative determinations of new additives should be validated, e.g. by calibration on the basis of more than one mother liquor, repeatability/reproducibility experiments or the use of SPC charts. The analyst must constantly be aware of unwanted interferences. For example, the presence of certain additives, particularly fillers and pigments, may cause serious interferences with the measurement of other additives present [23]. More trivially, contaminations of Chi-massorb 944 residues accumulated in a rotavapour may interfere with subsequent analyses. Care should... 

Case studies are used to demonstrate failures in polymer products. Aspects of defect analysis considered include the occurrence of recrystallisation, surface contamination, frozen-in strain, mixing efficiency, and formulation problems. Case histories examined include those involving pipes and fittings, storage tanks, and medical products. 383 refs. 

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