Recommended preservatives and maximum holding periods for most determinations made on wastes and waste waters are summarized in Table 2. Know which specific analyses are to be made on the sample. Collect representative samples. Avoid contaminating samples once they are collected. Immediately put samples on ice, or use the proper preservative.
Refrigeration is the only preservation method to be used on samples taken for biological analysis.
If there is doubt about the preservation method to use, store the sample on ice. Label all samples immediately and record them. List pertinent data on the label or accompanying letter. Keep the time interval between collection and analysis as short as possible. Copyright 1999 University of Missouri.