Sample Collection, Handling and Storage

Results from round-robin tests and inspection of variability of positive controls over time have indicated that laboratory precision (i.e. precision not related to sampling collection, handling and storage) seemed to be good for whole-sediment tests and in the... 

ISO 10381-6 1993 Soil quality - Sampling - Part 6 Guidance on the collection, handling and storage of soil for the assessment of aerobic microbial processes in the laboratory. 

The collection, handling, and storage of corrosion products should he in such a manner as to avoid contamination and/or degradation of the sample. Detailed examination should he carried out as soon as possible after removal from the system. 

Sample collection, handling, transfer, and storage procedures are steps in an analytical study that may offer an opportunity for loss of sample integrity and must be documented in detail. Registrants are responsible for the retention of their raw data which must be maintained as long as the registration, which it supports, is active. 

It is important that the equipment used for sample collection and the subsequent handling and storage of samples do not contribute to the contaminant load of the sample, for example, by leaching organics. The following are common materials used in sampling equipment construction (after Canter et al., 1990) ... 

Incorrect handling and storage of tissue sample that may degrade the thermolabile receptor proteins. During the collection, the specimen must always be kept cold and transported on Ice to its storage in a freezer at -70 C. 

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 ... 

Regardless of the type of dispersion and the nature of the technique(s) applied in the characterization, a key question is always whether or not a sample under study has been collected and prepared in such a way that it was and is still representative of the dispersion as it occurred in the original environment from which it was sampled. Particularly with foams and aerosols, and also with emulsions and suspensions, the sampling method can change the nature of the dispersion, as can the subsequent handling and storage methods used. A number of specialist treatises in the literature deal with this aspect in detail (see, for example, the references cited for particles [5], emulsions [6], foams [7], suspensions [8,9] and aerosols [10-12]). 

The main objective of analysis is to ensure the water supplied to the public meets the relevant standards and does not exceed the recommended concentration of hazardous chemicals. The analyses performed by the water laboratory for compliance purposes should be performed in an accredited laboratory and comply with the recognized standard for technical competence of testing laboratories. A complete analytical procedure should include information on sample handling (collection, transport, and storage), sample preparation (concentrate and separate), analysis (methods to identify and quantify components), analytical quality control (criteria), and reporting of analytical results. 

RAC samples from a processing study should be handled exactly as RAC samples from a field residue trial. They should be frozen as soon as possible following collection. Once the processing commodities have been created, they should be frozen and shipped to the analytical lab as quickly as possible. Both the RAC samples and processed samples from a processing study must remain frozen throughout the shipment and storage period of the study in order to preserve residue integrity. 

Each of the five main steps in field conduct (site selection, test plot layout, test substance application, sample collection, and sample storage/handling) is addressed below. 

Field recovery samples are an important part of the quality control in DFR studies. Field fortifications allow the experimental data to be corrected for losses at all phases of the study from collection through sample transport and storage. Fresh laboratory fortifications monitor losses due to the analytical phase. This section details how the field recovery process was handled in the oxamyl tomato DFR study. 

Trip blanks prepared in vials and containing aliquots of methanol or analyte-free water accompany soil samples collected in a similar manner for low concentration VOC analysis according to EPA Method 5035. In this case, field samples and trip blanks have the same contamination pathway when exposed to airborne contaminants and the same VOC transport mechanism. These trip blanks provide important information, which may enable us to recognize the artifacts of improper sample handling, storage, or shipping. 

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