Sample collection and handling

It is vital that environmental samples (such as effluents, leachates, receiving waters, sediments and soils) taken for testing with bioassays are considered representative and that the procedures adopted for the collection, storage and preparation of samples ensure that the toxicity of the sample obtained at source does not change markedly before a test is conducted. It is also vital that supporting documentation, in the form of a chain of custody record, accompanies the sample. 

Detailed information on procedures for the collection, handling and preservation of aqueous and sediment samples is given in a series of ASTM (1994a,b) and ISO (1990, 1991, 1992a,b, 1994, 1995, 1998a,b, 1999, 2000) documents. General issues for the collection, storage and preparation of environmental samples for bioassays that need to be considered are summarised below  

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The sampling took place between August 16 and 24, 1983. Most of the 274 samples collected for shipment to contract laboratories were to be analyzed for the purpose of more fully delineating contamination boundaries. Other samples were collected for comparing sample collection and handling techniques. 

OPPTS 860.1500, p. 16, indicates that 3-5 sampling points should be included in the decline trials. For applications close to the normal harvest time, the RAC may be harvested at selected intervals between the time of final application and a normal harvest or slightly delayed harvest. If the application is made long before the normal harvest, then representative plant tissues (including immature RAC) may need to be harvested in order to stretch the harvest period. A single composite sample is all that is required from each selected time point, but two or more samples may be harvested to reduce uncertainty about the actual amount of residue present at each sample time interval. These decline samples should be collected and treated the same as normal RAC samples. The samples should be frozen as soon as possible after collection. The instructions for decline sample collection and handling described in the protocol should be followed closely. 

Proper sample collection and handling are the key to acceptable agrochemical recovery at zero time. The zero-time sample interval is defined as the first sample collected after application. Zero-time soil samples should be collected within 3h after application. Zero-time soil core concentrations, such as those given in Table 3,... 

Extrinsic wastes are more functional in nature and are not necessarily inherent to a specific process configuration. These may occur as a result of unit upsets, selection of auxiliary equipment, fugitive leaks, process shutdown, sample collection and handling, solvent selection, or waste handling practices. Extrinsic wastes can be, and often are, reduced readily through administrative controls, additional maintenance or improved maintenance procedures, simple recycling, minor... 

Zhang N. et al., 2000. Integrated sample collection and handling for drug discovery bioanalysis. J Pharm BiomedAnal 23 551. 

Type of Container to Be Used. The specific type of contained used to collect blood or urine samples is sometimes indicated in a protocol, especially if a special anticoagulant or additive is required or if other specific conditions of sample collection and handling are required. It is generally not necessary to provide this information for commonly requested laboratory tests. 

The stability of an analyte in a particular matrix and container system is relevant only to that matrix and container system and should not be extrapolated to other matrices and container systems. Stability procedures should evaluate the stability of the analytes during sample collection and handling, after long-term (frozen at... 

Urine samples are collected and maintained as described in section Assessment of Renal Injury by Urinalysis . There are some special considerations in sample collection and handling that are critical to accurate assessment of urine enzyme activity (Vander-linde, 1981 Price, 1982 Plummer etal. 1986 Mueller et al. 1986, 1989, Loeb et al. 1997, Clemo 1998, Jung and Grutzmann 1988, Loeb 1998) ... 

Ahlers W. W., Reid R. M., Kim P. J., and Hunter K. A. (1990) Contamination-free sample collection and handling protocols for trace elements in natural fresh waters. Austral. J. Mar. Freshwater Res. 41, 713-720. 

The flow analyser is well suited for handling aqueous samples, which are directly inserted into the manifold by taking advantage of loop-based or time-based sample introduction. Due to the portability, ruggedness, low power requirement and low maintenance requirement inherent to the unsegmented flow systems, specific approaches for in situ sample collection and handling have been proposed. 

In addition, it provides all necessary precautions and specifics for using sample collection and handling equipment, along with specifics for the study concerned, for example, depth at which samples are taken, cross-sectional area sampled and precautions necessary to avoid contamination of samples. 

With attention to sample collecting and handling It will be possible to study effectively the occurrences and distribution of amino acids throughout the crust of the earth and even in regions (submarine vents, volcanic areas and extraterrestrial regions, etc.) where abiotic synthesis of amino acids has been suggested. Prospects are exciting ... 

Careful understauding of the effects of each preanalytical variable on the biomarker data is complex and necessitates a staged approach conceptually similar to the fit-for-purpose analytical validation of a biomarker assay (see Chapter 41). In the early exploratory phase of biomarker investigation, standardization of procedures with a defined protocol for sample collection and handling will permit comparative interpretation and analysis of the data within study and/or between studies. Minimally, variables that should be experimentally evaluated to optimize sample collection for a specific biomarker will include matrix type, preservation... 

As is stated in the Sample collection and handling section of this article, several postmortem factors may affect forensic ethanol testing in dead persons. Special care must be taken when evaluating effects of ethanol from its levels in postmortem fluid samples. 

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