The Metrohm 797 VA Computrace is a PC-controlled voltammetric measuring instrument that is capable of realising sub ug l-1 detection limits for a variety of transition metals.
The 797 can be used for at-line or portable analysis.
Its compact nature allows for instant analyses in the field, such as water stream examination for breach of consent limits.
Apart from the determination of the total concentration, voltammetry can also distinguish between the different oxidation stages of various metal ions.
Voltammetry differentiates between the free and bound metal ions to make statements about the biological availability of heavy metals.
Typically detection limits that have been determined for a number of important metals are: arsenic 100 ug l-1; chromium 25 ug l-1; copper 50 ug l-1; iron 50 ug l-1; lead 50 ug l-1; mercury 100 ug l-1; platinum 0.1 ug l-1; uranium 25 ug l-1; zinc 50 ug l-1.
When the sample is of a high ionic nature, high background conductivity poses no problems for voltammetry.
Key features of the 787 include: low price (currently less than GBP12,000 with intelligent Dosinos for addition of reagents); small size; recognised technique; standard addition calibration; high detection limits.
