Sample accounting

BaP, benzo[g/z/]perylene, benzo[6]fluoranthene, in-deno[l,2,3-cd]pyrene, and benzo[/c]fluoranthene, contribute the major portion of the identifiable mutagenicity of the extract of the whole unfractionated sample, accounting for 8.6, 2.5, 1.7, 1.4, 1.2, and 0.8%, respectively, of the total mutagenicity of the whole sample. Two semipolar mutagenic PACs were also present at significant levels 2-nitrofluoranthene, a product of atmospheric reactions, and 6//-benzo[c<7]pyren-6-one, a primary O-PAC pollutant present in exhaust emissions from diesel engines and non-catalyst-equipped cars (see Sections E and F). These account for an additional 0.8 and 1.6%, respectively, of the identified whole sample mutagenic potency (see Table 10.26). 

Using a simple mean to calculate the atomic mass will not work since the isotopes are not present in equal amounts. Therefore, we must take into account the percentage of the total sample accounted for by each isotope. To complete the calculation, simply multiply the mass of the isotope by the relative abundance (expressed as a decimal) and add the total values ... 

Sample accountability Sub-sample Test portion Test sample... 

A term related to integrity is sample accountability, which is the procedure by which the appropriate documentation regarding the sampling process and subsequent actions prior to analysis is established and maintained. The sample will have a unique identity and each stage of handling the sample will be documented so that its whole life cycle is traceable. Sample accountability is thus part of the audit trail (see Section 5.1) of a sample. 

The disordered structure (cf pore size distribution) of the sample accounts for the injection pressure dispersion. 

The increase in both surface capacitance and density of the activated samples account for added functional groups on the surface, as indicated for the samples F and G in... 

Sample Accountability Source records should identify the source and number of subject samples2 received by the bioanalytical laboratory, the date of sample receipt, the condition of the samples upon receipt, and the storage location (e.g., equipment identifiers) and temperature conditions for the duration of storage. Courier receipts of the sample shipment should be maintained in the study file. 

The vertical profiles of PAHs and PCBs that reflected their variance with depth and time were shown in Fig. 3.74. Sixteen individual PAH compounds recommended as the priority pollutants by US EPA were detected, with the results tabulated in Table 3.41. The concentrations of all individual PAH compounds (EPAHs) in each layer were summed up to evaluate PAHs levels. From surface to bottom, EPAHs ranged from 26.31 (24 26 cm) to 76.92 ng/g (14 16 cm) based on dry weight. In general, benzo(b)fluoranthene (B(b)F) was the prevalent component in most samples, accounting for 7% 16%. 

Arsenic concentration In the small sample accounted for 73.4% of the variation,... 

Extraction of nucleic acids from environmental samples accounts for a large fraction of the microorganisms that is not culturable but may be responsible for major biodegradation activities. 

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