Samples for nutrient analysis should be filtered through a 0.4um polycarbonate filter. Unfiltered, turbid, or samples with widely varying concentrations within a batch of samples may require dilutions or manipulations. These samples fall in the 'Other' category as found on the rate schedule. Samples should be collected in clean, pre-rinsed glass or plastic HDPE 20ml scintillation vials. Samples being analyzed for Si(OH)4 must be collected in plastic HDPE vials. For all other analytes, glass or plastic HDPE containers are acceptable. Some adsorption of PO4 during storage in plastic containers has been noted, so glass may be preferred if PO4 is to be determined. Caps should have a plastic liner. All foil lined lids should be avoided.

Storage blanks are required if NH4 is to be measured. Storage blanks are recommended for all other analytes to detect possible contamination.

A minimum of 5mL of sample is required for the determination of a single nutrient species. 12-17mL of sample is necessary for simultaneous determination of all analytes. It is entirely unnecessary to submit more than 20mL of sample. If you must submit more than 20mL of sample or have other volume concerns, please contact the Analytical Lab.

Mark all samples clearly and directly on the sample container, as well as the lid. If you plan on shipping samples, any masking tape or colored lab-style tape placed on sample vials will fall off during shipment if in the presence of dry ice. Do not use these types of tape to label samples if you plan on shipping samples on dry ice.

To preserve sample integrity, samples should be stored on ice immediately after collection and transferred to a freezer for storage until analysis.