Particulate Carbon, Nitrogen and Phosphorus: BCSS-1 is a marine sediment reference material prepared by the National Research Council of Canada. It is certified by the Council for carbon content, gives a non-certified range of results for phosphorus, but no information for nitrogen. We have analyzed this sediment for many years and maintain a substantial database for nitrogen and phosphorus, as well as carbon values. We analyze this sediment quarterly and compare these results to the certified value, non-certified range of values and our historical values.
Dissolved Analytes and Hardness: Standard reference materials for ammonium, nitrite + nitrate, nitrite, orthophosphate, dissolved nitrogen, dissolved phosphorus, dissolved organic carbon, sulfate and chloride and hardness are supplied by SPEX, a US EPA certified company. The samples arrive in ampules and we prepare final concentrations to approximate typical estuarine concentrations. The samples are then placed in pre-cleaned poly bottles, frozen and analyzed on a quarterly basis.
The analysis of these frozen standard reference materials as a function of time also provides data on the effect of our preservation technique (freezing) on the integrity of the concentration of samples. The US EPA recommends a holding time of 28 days for many of the parameters we routinely analyze.