Trace Metals/COD/BODs

Traditionally soils, sediments, sludges, foods and other materials have been digested using Aqua regia (a mixture of Hydrochloric acid and Nitric acid) as a preparation for the determination of their trace metals content.

These digestions have in the past been done in glass beakers on a hotplate, however modern standards in laboratories demand a greater level of control and accuracy.

C. Gerhardt UK can offer two solutions for trace metals analysis:

Gerhardt SMA Trace Metal digestion System

This is the ultimate in design and control of digestions for trace metals analysis. Built to comply with European Standard methods including ISO 11466:1995, DIN 38414 and BS 7755-3.9, the system features an aluminium hot block for 8 or 20, 250ml glass tubes, water condensers, cold acid traps and accurate time/temperature control.

Gerhardt SMA systems can also be supplied without acid traps for use in Chemical Oxygen Demand (COD) analysis.

Environmental Express Graphite Digestion Blocks

The Environmental Express HotBlock provides a convenient way of digesting large numbers of samples. HotBlocks are available to digest 36 or 54, 70ml tubes, 25 or 35, 100ml tubes or 96, 15ml tubes.

Digestions for trace metals are usually at a relatively low temperature and can be done in disposable flat-bottomed polypropylene tubes up to 135°C. Digestions at higher temperatures can be done in flat-bottomed glass tubes. The HotBlock temperature is limited to 180°C.

Polypropylene watch glasses are used to hold in condensation.

Optional controllers from simple on off through to fully time/temperature programmable systems are available.

Polypropylene tubes are supplied with screw caps and are graduated for ease of use. Tubes without caps are also available.

Environmental Express Biochemical Oxygen Demand - Disposable BOD Bottles

Environmental Express provides an easy way to handle BOD analysis. Disposable plastic BOD bottles are lightweight, unbreakable, safe and recyclable saving time on the preparation and cleaning of glassware for BOD analysis. Plastic BOD bottles have been thoroughly tested against glass BOD bottles to ensure accurate and comparable performance.

The Environmental Express BOD bottles are coated internally with a barrier to prevent oxygen diffusion through the walls of the bottle.

Plastic BOD bottles are supplied ready to use straight from the box without pre-washing. Each bottle is individually numbered for help with sample identification.

Once the analysis is complete the bottles can be recycled along with other PET plastics.

As an alternative to existing glass or plastic, Environmental Express also supply an acrylic stopper, which is required for BOD bottles. The stoppers are also very easy to wash and re-use, taking up little space.

Some methods insist on the use of an 'over cap' to prevent evaporation. These can be supplied, made in Polyethylene, which fit the disposable BOD bottles