An advanced TOC-TN analyser from Hach Lange has helped South West Water reduce downtime and maintenance costs for its inorganic chemistry laboratory.
The lab has used the IL 550 analyser for the past five months to analyse potable water as well as non-potable water (surface and ground water) and environmental samples such as landfill leachates as a dual application.
Tracy Churchill, senior assistant-scientist for South West Water, was part of the evaluation team that chose the new analyser for total organic carbon analysis.
She said: 'The IL 550 software is very user-friendly, making it easy to train analysts.
'Because the analyser has a stand-by mode we are able to leave the instrument on at a reduced temperature, which prolongs the life of the catalyst.
'As a result of these features we have significantly reduced downtime and maintenance costs, as previously we had to replace the catalyst on a fairly regular basis.' TOC and TN analysis is important in applications ranging from power generation, wastewater, drinking water, surface water and ultrapure water, to agricultural soils, contaminated land and food.
A key feature of the IL 550 is particle tolerance in liquids.
The autosampler needle has a large internal diameter and the sample is injected directly via the pneumatic port into the furnace: this eliminates blockages, cross-contamination or leaks because there is no septum or valve.
This also removes the need to filter wastewater samples because the IL550 measures the TOC of both liquid and solid particulates in a sample.
Samples are also stirred prior to injection to ensure homogeneity.
Total nitrogen can be measured from 0.1 to 100mg/l, by an internal electrochemical detector or with an optional chemiluminescence detector for testing to EN12260.
For maximum efficiency, digestion takes place up to 950C for the combustion version IL 550 and the solids module can increase the temperature to 1300C.
The UV version is equipped with a high-energy UV lamp, which offers the advantage of direct contact with the sample.
Effective digestion ensures complete sample oxidation, which improves accuracy.