Metrohm intelligent Partial Loop (MiPT) Technique for Improved Sample Preparation in Ion Chromatography

The ProfIC 15 AnCat is a Professional IC system for the fully automatic determination of anions with sequential suppression and cations with partial loop injection capability. Partial loop injection allows concentrated samples to be injected without previous manual dilution as well as multipoint calibrations from just a single standard solution.

A revised setup of the ProfIC 15 from Metrohm was designed to enable a flexible partial loop method and provide automatic calibration, improve the convenience, accuracy and reproducibility as well as faster sample handling times (around 3 minutes plus analysis).

The ProfIC 15 configuration forms one part of Metrohm Inline Sample Preparation (MISP) techniques. Quantification in ion chromatography requires a calibration that covers the defined measuring range. The necessary calibration standards are usually prepared from a concentrated multi ion standard by appropriate manual dilution. Calibration can be both time consuming and prone to errors. Using the fully automated MISP method it is possible to prepare a mg/L to ng/L calibration graph with no preparation of individual standards eliminating operational errors.

The ProfIC 15 configuration comprises the top of the line 850 Professional IC, 858 Professional Sample Processor and employs Metrohm’s patented Dosino liquid handling technology and the external rinsing station helps ensure virtually no contamination at trace levels. The 850 Professional IC is the first Ion Chromatography system with intelligent system components that are optimally configured to one another. The path from sample to a precise, accurate result has never been easier due to the in-built safe guards and intuitive nature of the controlling software.

Intelligence comes as standard with the 850 Professional IC systems:-

§ iPump with 15% less pulsation compared to previous generation design.


§ iDetector with a single range and test chromatograms for training use.


§ iColumn with intelligence and traceability of its analytical working life.


§ iDosing with Dosino technology for very precise liquid handling.


§ MagIC Net software with smart system control and monitoring of results.


The build quality of the system ensures low detection limits for both chemistries and precise results. Particular attention has been given to the long service interval that can be monitored and flagged by the MagIC Net software.

The AnCat system features features two iPumps as well as two iDetectors and provides space for a total of three iColumns in two different temperature environments within a single housing. The anion system is equipped with the novel sequential suppression and the unique combination of chemical and downstream CO₂ suppression results in very low detection limits. The flexibility of the carbonate eluent is complemented by the low background conductivity of a hydroxide eluent. The cation system operates using direct conductivity with a nitric acid or oxalic acid eluent with no compromise in detection limits. A major application benefit of working with direct conductivity is that transition metals like manganese and zinc can also be quantified. When a cation suppressor is employed for samples that contain transition metals these can precipitate out onto the suppressor leading to reliability issues and high running costs.

The Metrohm 800 Dosino ensures sample transfer with high precision and partial loop injections are performed easily and accurate results obtained when calibrating from a single standard solution. The size of the injection volume is automatically controlled by the MagIC Net software but using a 250µl fixed loop, the actual volume injected is adjustable between 2-200µl. The Metrohm Dosino is a proven, precise and extremely flexible dosing device. Liquid handling can be completely automated by using control procedures included in the IC software, the sample table serving as the user interface.

The different chemistries can either be run in parallel or independently of each other from a single Sample Processor. An external rinsing station located on the edge of the Sample Processor is essential for low level trace analysis and rinsing of the needle. Carry-over is not an issue due to the employment of the the reliable Dosino pull mode technique; tests have shown the carryover to be less than 0.001%.

All system parameters are monitored and optimised through the MagIC Net software with its smart control. Control cards for the calibration and samples can be freely defined and should an important parameter leave a predefined tolerance than the user is informed.

The ProfIC 15 AnCat system from Metrohm comes with a ten year suppressor warranty and a three year instrument warranty as standard – Metrohm IC is proven to have the lowest cost of ownership in the IC market place.