Drinking water samples, characteristics

To analyse the solvent extracts a lOpL aliquot of the concentrated extract was injected into a Finnigan 4000 gas chromatograph-mass spectrometer coupled to a 6110 data system. A 3% OV-17 provided the best separation of the detectable PAHs. Quantitative estimations of the detectable O-PAHs in Ottawa drinking water were obtained by comparison of the areas of the two characteristic ion peaks (Tablesl6.2 and 16.3) in the mass chromatograms of the reference standard and the field sample, respectively. No corrections were made for incomplete recovery. Of the 50 PAHs in the standard used by Benoit et al. [119], 38 are detected in at least one of the drinking water samples tested. 

It is shown that metrological characteristics of the suggested methods are commensurable. Dissolved gas is pushed away by front of crystallization, takes the air and does not influence on the obtained results during the analysis of the water. Process is carried out at the lower temperature (-15°C), expelling chemical transformations of ingredients. The procedure was tested on different samples of natural and drinking water of the Kharkov region. 

A number of biochemical markers not associated with the cell envelope allow the specific detection of individual microorganisms in environmental samples. These include secondary alcohols. For example, Mycobacterium xenopi can be detected through the hydrolysis of wax ester mycolates, which liberates 2-docosanol, a characteristic and dominant secondary alcohol, which can be detected at low levels by GC-MS. This biomarker was found to be very useful for the rapid detection of M. xenopi in drinking water (159,160). Results from the GC-MS detection of 2-docosanol were obtained within 2 days compared to the 12 weeks required for culturable detection of M. xenopi. The detection limit for this type of approach was found to be 10 colony-forming units (CFU) ml" drinking water. 

Snow, especially its water-soluble fraction, is one of the most sensitive and informative indicators of mass-transfer in the chain air - soil - drinking water. Therefore analytical data on snow-melt samples were selected for inter-laboratory quality control. Inter-laboratory verification of analytical results estimated in all the groups have shown that relative standard errors for the concentrations of all the determined elements do not exceed (5-15)% in the concentration range 0.01 - 10000 microg/1, which is consistent with the metrological characteristics of the methods employed. All analytical data collected by different groups of analysts were tested for reliability and... 

Gjessing, E. T., Egeberg, P. K., and Hakedal, J. (1999). Natural organic matter in drinking water—the NOM-Typing Project, background and basic characteristics of original samples and NOM isolates. Environ. Int. 25,145-159. 

Methodological approach basehne separation achieved within <10 min. The analytical performance characteristics studied (DL < 100 ng As L for all the species evaluated). The feasibility for the analysis of normal As levels in drinking water was demonstrated. However, it was observed that matrix composition and the sample treatment may affect natural As(in)/As(V) distribution... 

Based on the chemical quality of drinking water, we could separate sampling points that were supplied with surface water (1 sample), karstic water (3 samples), or mixed water (2) and points that were supplied alternately with surface or karstic water depending on pressure characteristics (2). 

Results from the evaluation of ground water quality characteristics near two waste sites in Ibadan and Lagos revealed that some of the ground-water quality constituents determined exceeded the World Health Organization (WHO) standards for drinking water irrespective of source of pollution. Some of the ground-water samples were poor in quality in terms of cadmium, chromium, lead and nickel recorded (Deem et al., 2002). The levels of heavy metals (cadmium, chromium, nickel, and lead) were analysed in the River Ijana (Ekpa-... 

A characteristic example of the performance of IC/ICP-OES is the spedation of chromium [190,191]. Due to it widespread use in industrial applications such as chromium plating, dye manufacturing, and preservation of wood and leather materials, chromium concentrations in environmental samples are monitored on a routine basis. Both the US EPA and the European Union have specified maximum admissible chromium concentrations in their respective drinking water directives. As with many other trace elements, chromium (Cr) is typically found in more than one chemical form, each of which with different chemical properties and behavior, such as bioavailability and toxicity. The spedation analysis of chromium is a challenging task, since the stability of different chromium species is easily affected by conditions during sample collection and treatment. For... 

Provide a deeper insight into the behavioural characteristics of the stagnation sampling methods used in the regulation of lead in drinking water. 

Plumbosolvency characteristics also strongly influence the results of sampling for lead in drinking water and can be... 

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