IRRI SERVICE LABORATORIES
provides quality and efficient integrated laboratory testing services and expertise
Water/soil extract sample preparation and submission guide
The most important aspect of water analysis is knowing how to take a representative sample. Planning is an important step that must be done in order to address factors that need to be controlled. Sampling plan and method must be available during sampling and must be properly executed to ensure sample integrity. Results are only as good as the samples collected and the method used for its preparation. Because only a small amount of sample is used for any particular test, it is essential that sub-samples are carefully selected and thoroughly mixed, and the quantity prepared should be at least 10 times greater than the final sample analyzed.
Refer to the list below for the minimum sampling size and sample size required for sample submission and laboratory analysis. Water or soil extract samples may be stored in glass (except for boron analysis) or plastic containers with caps.
Samples for analysis must be properly labeled to avoid sample misidentification. Label sample/s with the following information:
- Sample identification/description
- Customer name
- Requested test parameter/s
Submit the labeled sample/s with accomplished sample ID list form.
For nitrogen analysis of soil extracts, please submit at least 1 l of matrix or extractant for preparation of laboratory standard calibration solution.
For dissolved metals in water analysis, submit field blank (sub-sample of 1 l deionized water, exposed to sampling environmental condition, filtered using 0.45-um, and preserved with HNO3 to pH < 2).