Total organic content

It is important to identify volatile organic carbon (VOC) and the presence of specific priority poUutants, ia additioa to the total organic content. The... 

The microorganisms in sewer biofilms are embedded in a matrix of EPS that consists mostly of polysaccharides produced by the bacteria (Characklis and Marshall, 1990). The EPS fraction is the largest organic fraction in the biofilm, i.e., up to about 90% of the total organic content. Only limited studies of the total composition of sewer biofilms in terms of carbohydrates, proteins and humic substances have been undertaken (Figure 3.12). Corresponding information on the composition of anaerobic biofilms in pressure mains does not yet exist. 

For solution preparation, only water of 18.2MO-cm and total organic content of less than five parts per billion should be used. 

After heating, the sample turned bulklike with black color, and EDX data showed that the residues contained S in addition to a large amount of I and Ag. X-ray diffraction patterns of the residues gave the main diffraction peaks of Agl, indicating that the residues were mainly Agl crystallite. Total mass losses of samples 1-VI obtained from TGA lie between the total organics content and total mass amount of C + H + O in the samples from the elemental analysis, for which the data are tabulated in Table 4.4.4. The difference may be caused by the residual S in the particle surface. This result supports that heating mainly resulted in the decomposition of organics in the powders. 

Table 4.4.4 Comparison of Mass Loss from TG of Agl Samples with Total Organics Content and That of the Sum of C + H + O from the Elemental Analysis...

Field-collected sample of presumably clean (uncontaminated) sediment, selected for properties (e.g., particle size, compactness, total organic content) representing sediment conditions that closely match those of the sample(s) of test sediment except for the degree of chemical contaminants. It is often selected from a site that is uninfluenced or minimally influenced by the source(s) of anthropogenic contamination but within the general vicinity of the site(s) where samples of test sediment are collected. A reference sediment should not produce a toxic effect (or have a minimum effect) on a test species. A sample of reference sediment should be included in each series of toxicity tests with test sediment(s). See also Artificial sediment, Positive control sediment and Test sediment. Volume 1(2,13), Volume 2(8). 

All buffers and solutions were prepared in desalted water with a conductivity below 18.2 mS and a total organic content below 2 ppb (parts per billion) using a ELGA PURELAB Ultra system (ELGA Lab Water, Celle, Germany). 

Polyallylamine (Mw = 70 000 g/mol) and polystyrene sulfonate (M, = 70 000 g/mol) were obtained from Aldrich. PAH was used as received, while PSS was purified from low molecular weight impurities by dialysis (Polyether-sulfone membranes, MW cut off 10 000 g/mol, Millipore) against ultra pure water and freeze dried. All water used for preparing solutions or for dialysis was purified by a Purelab Plus UV/UF, Elga Lab Water system and had a resistivity smaller than 0.055 xS/cm and a total organic content between 2 and 12 ppb (parts per billion). 

Solutions (including doubled distilled water, buffer and culture medium) should be sterile and DNase- and RNase-free grade and stored at 2-8°C (+4°C) after opened. Unless stated otherwise, all solutions should be prepared in water that has a resistivity of 18.2 MU cm and total organic content of less than five parts per billion. This standard is referred to as doubled distilled water in this text. 

The HF/HC1 extraction results in the removal of approximately 96% of the elemental Si present as well as approximately 90% of the A1 (see Table III). The total amount of HF/ether extracted organics is at least 1.72 and 1.34 wt% of the total organic content in the 104 and 184 L/t oil shale. Approximately 1.64 and 2.00 wt% of the total organics are trapped by the silicate minerals as determined by the results of the third benzene/methanol Soxhlet extraction for the two different shale richnesses. The above results are summarized in Table IV. 

The concentration for the sum of organic compounds was calculated as the difference of the total organic content and the formaldehyde measurements shown in Table 1. 

The amount of organo-chlorine compounds in the sediment needs to be related to the amount of dry matter and to the organic content of the sample. These should be determined separately by determining the moisture content of the sediment by drying a weighted amount in an oven at 105°C, while the total organic content is determined by igniting in a muffle furnace or chemical oxidation with chromic acid. 

Despite the positive ecological properties of water-based paints, they also cause some problems. It has been shown in [203] that the average total organic content in the booth water... 

Only ASTM Type 1 (American Society of Testing and Materials) water of 18 MOhm purity with less than 5 ppb Total Organic Content is recommended if buffers are prepared in the laboratory. Do NOT use autoclaved water (for PCRs as well) because there may be metal ions and/or organic contaminants present. Buffers are flammable and irritants. Proper laboratory safety must be exercised... 

The water used for preparing parenteral solutions needs to meet USP requirements for water for injection. These requirements include bacterial endotoxins no greater than 0.25 eu/mL, total organic content less than 500 ppb, and a conductivity of 1.3 iS/cm. Water for injection is prepared by distillation or a two-stage RO process. A typical process to produce water for injection consists of multimedia filtration, softener, activated carbon, 1-5 qm preflltration, UV treatment, two-stage RO, mixed DI, UV, and sterile filtration. 

Total organic content = 1.2%, pulse heated B-21 Beeswax... 

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