Find out everything you need to know about water in oils and fuel at PEFTEC

When directly injecting your oil and fuel samples, many problems can occur when using coulometric Karl Fischer titration. Additives used in lubricating oils, fuels and mercaptans in crude oils cause side reactions when the sample is injected directly in to the titration solvent.

To counter this problem, an external oven is used, in most cases, a head space oven where the sample is heated in a sealed vial and the water extracted.  Nitrogen is used as a carrier gas which flows through the oven and titration vessel comprising of a gas outlet…

This technique certainly combats the problems associated with these side effects, but also has its own problems… Firstly, a blank value is required or to put it simply, a measurement of water inside an empty head space via  Depending on the vial and conditions, the blank can vary from 30-80 micrograms of water. This value will change and fluctuate during the day so it is recommended to perform the blank check regularly.  When using a detection technique as sensitive as coulometric Karl Fischer,  these estimated blank values are simply not good enough when requiring real ppm accuracy. 

When analysing trace water like in an insulating oil of say 10ppm,  having a blank value potentially much more than 5 times greater means you simply cannot rely on the result and in many cases, the instrument displaying 0ppm.

Another problem associated with an external  carrier gas,  is the fact that the system is regarded as “open” so the methanol in the Karl Fischer solvent quickly evaporates causing immediate instability.

ECH elektrochemie halle, who will exhibit at PEFTEC on stand 44, have totally addressed the above issues with the closed loop oil evaporator which is available on the new Aquamax KF Pro Oil.

The oven is connected directly to the titration vessel via a pump and tubing which circulates the carrier gas in a “closed loop”. The sample is injected from your sample syringe directly in to the oven removing the necessity of a blank value. As the methanol cannot evaporate we can now analyse over 1000+ samples without changing the reagent. All this and of course just like the alternative head space technique, ECH eliminate all of the negative side effects.    

ECH’s closed loop principle, featured on the Aquamax KF Pro Oil, ensures real 1 ppm accuracy, the longest reagent life cycle and with the patented temperature ramp program, ECH clearly identify the free water and the chemically bonded water. In summary, the Aquamax KF Pro tells you everything you need to know about water in your oils and fuels.