In the fourth installment in our series about the history of ion chromatography development at Metrohm over the years, we now focus on some of our combined analysis techniques. These are unique combinations of Metrohm instruments from different product groups which broaden application possibilities beyond what IC could accomplish alone. The TitrIC and VoltIC systems will be discussed in this installment.
TitrIC: combining titration, direct measurement, and IC in one
The combination of titration, pH, and conductivity measurement, as well as ion chromatography in a single analytical system was introduced in the late 1990s. This TitrIC system consisted of a Titrino for the determination of the p- and m-value (alkalinity), pH and conductivity meters, as well as a modular IC from the 732 IC Detector generation.
Depending on the analysis requirements, either a second Titrino (for the Ca/Mg water hardness determination) or a second IC channel (for alkali and alkaline earth metal cations as well as ammonium) was selected. The latter enabled an automatic determination of the ion balance for the first time.
The central unit is the autosampler, which directs the water sample to the titration/metering section and to the ion chromatographs. The respective titration software controls the titrators and pH/temperature meters, calculates the results, and transfers them to the IC software (at the time, IC Net). The IC software controls the ion chromatograph and creates the final report. The user only communicates with the master software, making comprehensive analysis a simple task. This combination was available in all Metrohm IC generations (Figures 1 and 2). The most current setup (TitrIC Flex I and II) combines the 930 Compact IC Flex instruments with OMNIS titration.
VoltIC – Voltammetry and IC
Just as with titration, it also is possible to combine IC and voltammetry in order to further expand application capabilities for enhanced trace measurement of analytes in water. VoltIC Professional integrates these techniques in a single, fully automatic system that is controlled via a common software, providing users with the strengths of both IC and voltammetry. Anions, major cations as well as trace cations may be detected in one determination.
Back in 2012, the original VoltIC pro system was launched to bridge the gap between these two techniques and to offer a unique solution to the market. In 2013, the new line of 940 Professional IC Vario instruments came along. A few years later in 2016, the 884 Professional VA analyzer was brought to the market, and thus VoltIC on the next level: the current VoltIC Professional system (Figure 3).
In Part 5 of our series, we describe the use of ion chromatography for continuous air monitoring with the MARGA from Metrohm Process Analytics.