Halogenated organic compounds (HOC) have increasingly been used within various industries over the years. Some man-made halogenated compounds are toxic, mutagenic, or carcinogenic and they may have harmful effects on human health and the environment.
Adsorbable Organic Halogen (AOX) Compounds (X = Cl, Br, I)) is a sum parameter for describing the organic halogen compound load in water, sewage sludge and soils. The parameter covers a large group of substances from simple volatile substances such as trichloromethane (chloroform), or complex organic molecules such as dioxins/furans with a large variety of toxic properties. Most AOXs are chlorine-containing molecules, but bromo- and iodo-AOXs do also occur.
AOX compounds pose a potential concern because they resist breaking down in the environment, and therefore they have long half-life periods. Some of these molecules toxic and can pose a threat to aquatic organisms living in estuaries because they can bioaccumulate in the food chain. Hence, AOX can be important in effluent quality monitoring from both landfill leachates, and industry, in order to meet discharge limits.
There are a number of AOX/TOX regulations in force, for example, DIN ISO 9652, EPA 1650 for AOX in water and wastewater, and EPA 9020B for TOX in wastewater.
The overall concept is relatively simple; the AOX compounds will adsorb onto activated charcoal under certain conditions so once the sample has been acidified, we can collect the AOX onto the charcoal, combust the charcoal and measure the AOX using microcoulometric titration.
The Multi X 2500 is suitable for all matrices, is more than ‘just’ an AOX analyser as it is also suitable for EOX, POX, TOX, TX and TOC applications, and works with a range of autosamplers and sample preparation systems to ensure that there is a configuration that will suit your requirements.
If you are looking to analyse solid samples (typically sludge, sediment, paper and pulp) then we can provide the AFU 3 sample preparation unit.
For liquid analyses we offer a range of sample preparation systems that fit the requirement of your laboratory and sample matrix.
If you have liquid samples then one of the first things you need to consider is whether you need to perform an SPE extraction before the AOX adsorption. One example of needing to do this extraction first would be in the event of high levels of inorganic chlorine in your sample.
We have a range of sample prep systems that will do this SPE extraction for you.
All of the APU 28 sample preparation systems can be used with a variety of different sized AOX adsorption columns.
We have a choice of autosamplers available fpr the analysis of solids and liquid samples
The double furnace design allows complete flexibility for all sample types.
The vertical furnace is particularly suited to liquid samples where there is choice of analysing just the active charcoal or the complete container, and the horizontal furnace can analyse up to 112 solid samples in one run.
To analyse for AOX we use a unique patented wide-range coulometer; it has a lightproof cell, is Peltier cooled and has a self-cleaning silver anode.
It has a very wide working range of 10 ng Cl (absolute) up 1000 ug Cl (absolute)
The electrolyte solution can’t become ‘exhausted’ during use
It requires no diaphragm or salt-bridge, and is maintenance free
The Multi X 2500 analyser is the highest performing AOX analyser available and can be extended to EOX, POX, TOX, TX, TC, TIC and TOC applications.
Whatever your sample, whatever your halogen – we can analyse it.
The following application notes are available ( on request):
Make reference to the relevant applicaiton note for it to be sent to you by one of our product managers
A detailed flier is available on request as a PDF document:
To find out more about the Multi X2500 AOX analyser, CLICK HERE