Reporting analytical methods

This guidance details how data stewards should report analytical methods when uploading data to DataStream, to support a consistent approach across datasets. This information is essential for the interpretation and re-use of data. It also allows secondary users to determine if data is comparable across datasets. The more information, the better.

DataStream requires that analytical methods are reported for samples analyzed in a laboratory. Data reports provided by commercial laboratories usually include information about the analytical methods used to produce the results. Data stewards can also provide information on how data was collected in the field (e.g. the brand name and model of the equipment).

DataStream’s data schema aligns with the Water Quality eXchange (WQX) data format developed by the U.S. Environmental Protection Agency and U.S. Geological Survey.

For details on how to choose the correct characteristic metadata, see:

• DataStream Upload Template
• Best practices for reporting nutrient data
• Best practices for reporting isotope data
• Best practices for reporting metals data

Analytical methods should be reported using the fields ResultAnalyticalMethodID, ResultAnalyticalMethodContext, and ResultAnalyticalMethodName (Table 1).

DataStream requires all lab-analyzed samples to include:

• Both ResultAnalyticalMethodContext and ResultAnalyticalMethodID, OR

• ResultAnalyticalMethodName, OR

• All three

The name of the laboratory should be reported in the LaboratoryName field.

Table 1: DataStream fields used to report analytical methods

If established standard analytical methods were used, the method publisher (e.g., “USEPA”, “VMV”, “APHA”) should be entered in the ResultAnalyticalMethodContext (“Context”) field, and the method code (e.g., “200.8”) should be reported in the ResultAnalyticalMethodID field (Table 2). A list of allowed values for method publishers that can be entered in the ResultAnalyticalMethodContext column is available in Table 4, or in the DataStream Upload Template on the Allowed Values tab.

Table 2: Format for reporting established standard methods

If a commercial laboratory used a custom or internally developed method, the ResultAnalyticalMethodContext should be “PROPRIETARY”, with the laboratory method code reported for ResultAnalyticalMethodID. However, if the methods used are considered equivalent to established standard methods (e.g. USEPA, APHA, etc.,), the standard method codes should be used in place of proprietary laboratory codes. This improves consistency in method reporting and facilitates data use for secondary data users.

If methodology originates from a published scientific article, this should be reported by entering ‘DOI’ (i.e. Digital Object Identifier) for the ResultAnalyticalMethodContext, and the actual publication DOI (e.g., https://doi.org/10.25976/ty8w-fv) for ResultAnalyticalMethodID.

Table 3: Format for reporting methods described in a scientific publication

When the method publisher and/or codes are not available, ResultAnalyticalMethodName should indicate the name or description of the method used or provide a reference for the protocol. This field can also be used to enter information on the instrument used for analysis (e.g., ICP-MS, ICP-OES), or the analytical method.

When a lab sample is calculated, DataStream requires analytical method fields to be populated. In these cases, if no calculation details are provided, we recommend populating ResultAnalyticalMethodName with ‘Calculated’. If there are details about calculations available, a detailed description in the ResultAnalyticalMethodName is recommended. If the calculation is referenced or summarized in a peer reviewed journal, the ResultAnalyticalMethodContext ‘DOI’ can be used with the DOI number listed in the ResultAnalyticalMethodID

If you don’t see a ResultAnalyticalMethodContext appropriate for your dataset, let us know, and we can add it to the list.

Table 4: Allowed values for ResultAnalyticalMethodContext

This guidance was prepared in collaboration with Dr. Megan Thompson of Thompson Aquatic Consulting.

Labs have different ways of reporting sample analysis results to their clients. DataStream collaborates with many labs across Canada to support monitoring groups with data formatting.

Our Data Specialists can work with you to ensure that the data and metadata provided by your lab are appropriately included in your dataset. This will prevent issues with your upload and ensure consistent reporting of water data (see Data schema).