Commonly Used Sample Preservation Techniques for Laboratory Water – Table 7 (Bioanalysis of Animal and Plant Groups C)

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The table lists the requirements for water sample preservation techniques. The preservation time, container material selection, and preservation measures all depend on the components and properties of the sample. However, real-world water samples vary greatly, so the requirements listed in the table cannot be absolute guidelines. Therefore, each analyst should verify the applicability of these requirements in their specific work, and the methods for sample collection and preservation should be clearly specified when developing analytical method standards.

Furthermore, if there are incompatibilities between the analytical method to be used and the preservatives and container materials, it is often necessary to take several samples from the same water body and analyze them using different preservation methods to determine the most suitable preservation method and container.

Common Sample Preservation Techniques – Table 7

(This table only contains general requirements for sample preservation. Due to the complex properties of natural water and wastewater, the stability of each type of sample treated according to the following methods needs to be verified before analysis.)

1 Project to be tested		2 Container Category	3 Save method	4 Analysis location	5 Storage time	6 suggestion
The bioanalytical items listed in this table are not exhaustive and only represent those commonly involved in research on plant and animal communities.	Identification and Counting (1) Benthic Invertebrates – Large Samples	P or G	Add 70% (v/v) ethanol and 40% (v/v) neutral formaldehyde (adjusted with sodium borate) to make the water sample a solution containing 2-5% (v/v).	laboratory laboratory	1 year 1 year	The water in the sample should be poured out first to achieve the maximum concentration of preservative.
	Small sample (e.g., reference sample)		The mixture was then transferred to a preservative solution containing 70% (v/v) ethanol, 40% (v/v) formaldehyde, and glycerin in a ratio of 100+2+1.	laboratory		Beware of formaldehyde vapor! It should not be stored in large quantities within the work area.
	(2) Aquatic periphytes	G	Add 1 part volume of sample to 100 parts Ruger's solution. The Ruger's solution is prepared by adding 150g potassium iodide, 100g iodine, and 18mL acetic acid (P=1.04g/L) per liter to make an aqueous sample. Store in a cool, dark place.	laboratory	1 year
	(3) Phytoplankton and zooplankton	G	See "Aquatic Peripheral Organisms" and add 40% (v/v) formaldehyde to make 4% (v/v) formalin, or add Ruger's solution.	laboratory laboratory	1 year 1 year	If decolorization occurs, add more Ruger's solution.