Abstract: The invention relates to an analysis device with a multi-way valve which is connected, via a pump line, to a bidirectional pump. A storage member for storing a sample fed to it and any auxiliary substances is accommodated in the pump line. The multi-way valve is connected, via two separate discharge lines, to an analysis vessel. The multi-way valve and the pump are controlled, with the aid of a microprocessor, in such a manner that the following steps are carried out:a. connecting a first feed line to the pump line via the multi-way valve, in order to feed sample to the storage member,b. using the pump to suck the sample into the storage member,c. connecting the pump line, via the multi-way valve, to a first discharge line which opens into the analysis vessel,d. feeding some of the sample present in the storage member to the analysis vessel via the pump and via the first discharge line,e. connecting the pump line to the flushing line via the multi-way valve,f.

Abstract: The invention relates to a method of determining an ion concentration with the aid of an ion-selective electrode, in which method a known quantity by volume of a sample is taken, a buffer is added and the initial potential of the electrode pair is measured, a known volume having an accurately known ion concentration is added and the potential obtained is measured, the standard solution being added stepwise, and the initial potential of the electrode pair and the slope of the relationship between potential and logarithm of the concentration is calculated for each of the quantities added from the data obtained, a small quantity of the solution to be determined is added, the potential difference is measured and the latter is compared with the required sudden change in potential, after which a sample is again taken and a quantity of the solution to be determined is added which is expected to bring the sudden change in potential into the required region, the potential is then read off and the required concentratio