A freshwater bioprobe: Periostracum of the Asian Clam, Corbicula fluminea (Müller) combined with laser microprobe mass spectrometer

A freshwater bioprobe, combining the Asiatic Clam, Corbicula fluminea (Müller) and the laser microprobe mass spectrometer (LAMMA), can determine anthropogenic chemical contamination of freshwater systems. Laser generated mass spectra from the periostracal layers of clams contaminated with either a salt, potassium bromide, or an aromatic compound, phenol, produce distinctive mass spectral signatures that are different from uncontaminated clams. Uncontaminated clams have characteristic signatures with distinctive spectral peaks less than m/z 41; while exposed clams have many strong peaks well above this m/z. This freshwater bioprobe, using LAMMA to analyze the surface of clams, can be used as a screening tool for monitoring the water-treatment systems, for determining the source of contaminated baseflow and return flow discharge to streams, and for monitoring the water chemistry of a body of water. This system exploits the facility of using the shell instead of soft tissue with the LAMMA and has potential to detect anthropogenically-derived chemical stress.