Environment samples

Bulk Samples Bulk samples must be submitted for all silica analyses. They have two purposes (1) For laboratory use only, to confirm the presence of quartz or cristobalite in respirable samples, or to assess the presence of other substances that may interfer in the analysis of respirable samples. (2) To determine the approximate percentage of quartz (or cristobalite) in the bulk sample. A bulk sample submitted "for laboratory use only" must be representative of the airborne free silica content of the work environment sampled otherwise it will be of no value. The order of preference for an evaluation is ... 

Specifications Chemical, Physical, Quality, Environment Sampling, Vapors, Dusts, Noise,... 

Fig. 7.2 Comparison of the proportion of elephants responding with chemosensory behaviors to the general substrate (environment) and to urine/feces for pre- and post-pubescent males and females, (a) Ndarakwai Ranch, Tanzania sample size of different elephants from left to right for environment and to urine/feces 40, 44, 46 and 40. The same animals were observed for response to urine/feces as to the environment, (b) Addo Elephant National Park South Africa sample size from left to right for environment 59, 43, 53 and 48. Many of the same animals were observed for response to urine/feces as to the environment. Sample sizes to urine/feces from left to right 49, 32, 44 and 44...

Analysis and Fate of Surfactants in the Aquatic Environment Sample Preparation for Trace Element Analysis Non-destructive Microanalysis of Cultural Heritage Materials Chromatographic-mass spectrometric food analysis for trace determination of pesticide residues... 

Bishop, J.N., Taylor, L.A. and Neary, B.P. (1973) in The Determination of Mercury in Environment Samples, Ministry of the Environment, Ontario, Canada. 

In addition to a general introduction to surfactants, the book comprises a comprehensive variety of analytical techniques, including sample handling, for the analysis of surfactants in the aquatic environment. Sample preparation includes automated solid phase... 

Although mirex was identified at 7 of the 1,408 NPL waste sites (HazDat 1994), it is not known at how many of the sites environment samples were analyzed for this compound. Currently, hazardous wastes sites may still be potential sources for release of this compound to soil. 

Methods exist for determining mirex and chlordecone in air (ambient and occupational), water, sediment and soil, biota and fish, and foods. Most involve separation by GC with detection by ECD or MS. Tables 6-3 and 6-4 summarize some of the applicable analytical methods used for determining mirex and chlordecone, respectively, in environment samples. 

Exogenous sources such as a person s hair or skin, doorknobs, laboratory benches, dust, reagents, thermal cyclers, and pipet tips are some of the common sources of DNA contamination. Ideally, a laminar air flow bench with filtered air provides a clean, dust-free environment. Sample preparation should be done in a separate room or area. The addition of sample to the PCR reaction mixture in the... 

The requirement for simplicity of sampling and analyzer operation is even more essential within a plant environment. Sampling must be highly reproducible and require only a minimum of operator skill. One must not second-guess an operator when designing either the sample-analyzer interface or the nser interface of the analyzer. Keystrokes for any operation must be kept to a minimum, and where practical, devices such... 

G.S. Sayler, M.S. Shields, A. Breen, E.T. Tedford, S. Hooper, K.M. Sirotkin and J.W. Davis. 1985. Application of DNA DNA colony hybridization to the detection of catabolic genotypes in environment samples. Appl. Environ. Microbiol. 49 1295-1303. 

The frequency of sampling will depend on the criticality of specified sites and the subsequent treatment received by the product after it has been aseptically processed. Table 9 shows suggested frequencies of sampling in decreasing order of frequency of sampling and in relation to the criticality of the area of the controlled environment sampled. 

Figure 4. A limiting distribution for evaluating acute exposures (solid line) sample distribution No. 1 comes from an unsafe environment sample distribution No. 2 comes from a safe environment.

Matrix Considerations Non-volatile and thermally fragile molecular samples are dissolved in a liquid matrix for introduction into the spectrometer to perform FABMS measurements. The properties generally Imposed upon the matrix include ability to dissolve samples and possession of low vapor pressure to extend life time in the vacuum environment. Sample life time should be several minutes to be able to optimize the spectral signal and make several spectral runs. Many organic liquids that satisfy these requirements have been used to obtain FAB data by several investigators (7, 31, 32). Two of the more often used matrices are glycerol and thioglycerol In addition, a liquid metal matrix was used to float the sample to obtain FABMS spectra (33). 

Figure 10. Fracture surface of a nylon filament exposed to an SOz environment. Sample was held at 70% strain for 4 days at room temperature. Magnification (a) ca. 1430X (b) ca. I430X (c) ca.

Whenever possible, a background sample of similar composition as the authentic sample is collected. For background sampling, the same type of sample collection equipment and techniques are applied as that used while collecting the authentic sample(s). Representative background samples will help to determine whether there are matrix effects, which may interfere in the sample preparation and analysis. Background and blank samples are required to determine whether the environment, sampling equipment, sample preparation, and analysis procedures alter the analytes of interest in the sample or interfere with the analysis. 

In most situations encountered in analyzing filters collected in either the workplace or the ambient environment, sample dissolution with nitric acid or a mixture of nitric and perchloric acids is adequate to obtain quantitative results. Since use of perchloric acid requires special fume hoods and is recommended only for chemists well trained in safe methods for use of this... 

This chapter has outlined the main effects of arsenic and selenium on human and animal health, their abundance and distribution in the environment, sampling and analysis, and the main factors controlling speciation and cycling. Such information should help to identify aquifers, water resources and soils at risk from high concentrations of arsenic and selenium, and areas of selenium deficiency. Human activity has had, and is likely to continue to have, a major role in releasing arsenic and selenium from the geosphere and in perturbing the namral distribution of these and other elements over the Earth s surface. 

All indexes collapse, in a somewhat arbitrary fashion, the numerous dimensions that comprise them into a single number that is treated as an accurate measurement of the condition of the area or environment sampled. Of course, the variables that comprise the index and, indeed, the values assigned to the components are often based upon professional judgment. Indexes can be... 

It is possible to produce artificial matrix materials [12]. Such materials can be prepared on a mass basis by weighing all components both to mimic the matrix composition and the content of trace elements or trace organic substances. The materials could help to have matrix materials available for which the exact contents and composition are known. As a consequence it would be, in theory, possible to certify them on a mass basis and validate methods with highly traceable materials. In organic trace analysis this would circumvent the unknown extraction step. In reality, this is much more difficult to achieve than can be expected. The real matrix composition of many materials is unknown — in particular for environment samples. The physico-chemical status of the various substances depends on the history of the material. Therefore, various natural samples of expected similar composition are different in behaviour. In addition, when preparing mixtures of solid components, losses cannot be excluded and unfortunately are not quantifiable. Attempts have been made where losses were demonstrated but not quantified [12]. Therefore, materials certified for matrix composition and analyte content on a mass basis do not yet exist or are not of real use for method validation by routine laboratories. They may be of interest for laboratories active in the field of fundamental research in chemical metrology where smaller quantities of material are handled. 

Department of the Environment, Sampling Strategies for Contaminated Land, CLR 4, Department... 

Spangler W.T., Spigeralli J.L., Rose J.M., Filippin R.S. and Miller H.H. (1973) Detoxification of methyl mercury by bacteria isolated from environment samples. Appl mocrobiol 25 488 193. 

Sampling station locations are shown in Figure 1 and the results of gas chromatographic analysis of the pentane fraction given in Table I. Figure 2 summarizes the average amount of aliphatic hydrocarbons obtained in the various environments sampled. Standard deviations and other details are summarized in Table II. 

Unless these questions are asked and answers are determined without ambiguity, before the collection of any environmental samples, there can be little confidence that the data derived from the analysis of the environmental samples, regardless of the precision and accuracy of the laboratory tasks, can provide useful or reliable insights as to the true state of the environment sampled. 

Sunesson A.L. (1995a) Volatile metabolites from microorganisms in indoor environments-sampling, analysis and identification. Thesis, Umea University, Sweden. 

Sunesson A.L., Nilsson C.A., Carlson R., Blomquist G. and Andersson B. (1995d) Influence of temperature, oxygen and carbon dioxide levels on the production of volatile metabolites from Streptomyces albidoflavus cultivated on gypsum board and tryptone glucose extract agar. In Sunesson A.L., Volatile metabolites from microorganisms in indoor environments-sampling, analysis and identification. Thesis, Umea University, Sweden. 

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