CASS-5 Nearshore seawater reference material for trace metals

This certified reference material is primarily intended for use in the calibration of procedures and the development of methods used for the analysis of seawater for trace metals.

The water was collected July 2007 from Halifax Harbour, at a depth of 12 m and has a salinity of 33.5. The sample was peristaltically pumped through cleaned polyethylene lined ethyl vinyl acetate tubing and 0.45 μm acrylic copolymer filters. It was acidified to pH 1.6 with ultrapure nitric acid during its immediate transfer to 50-litre acid leached polypropylene carboys previously conditioned with ultrapure water acidified to pH 1.6. In a clean room at NRC the seawater was later refiltered through 0.2 μm acrylic copolymer filters, homogenized in a precleaned polyethylene tank and bottled in cleaned 500 mL polyethylene bottles. The bottled water was gamma irradiated to a minimum dose of 25 kGy at the Canadian Irradiation Centre, Laval, Québec, to inhibit any bacterial action.

The certified values for CASS-5 are considered valid until August 2019, provided the CRM is handled and stored in accordance with instructions herein.

Keywords: Environmental material, Natural water, Seawater , Trace elements, Heavy metals