945 Professional Detector Vario IC Amperometric Detector Amperometric detection for determining electroactive components

Amperometric detection: the answer for complex analytical tasks 02 Amperometric detectors are an alternative to conductivity and UV/VIS detectors. They may always be used when electroactive − i.e., oxidizable or reducible − components are to be de­­ mined. The IC Amperometric Detector ter­ excels by its high selectivity and measurement sensitivity. It can be used for sensitive and accurate determination of concentrations down to the ng/L range. The amperometric detector is available as a detector block (the IC Amperometric Detector) and as a stand-alone detector (the 945 Professional Detector...

Highlights • Amperometric detector for determining electroactive components • Flexible setup as stand-alone detector or detector block for IC and HPLC • Outstanding selectivity due to different measuring modes: DC, PAD, flexIPAD, CV • High sensitivity through excellent signal/noise ratio • Large measuring range for demanding applications • Easy to use due to intelligent and robust measuring cells with wall-jet and thin-layer design • Large variety of working electrodes: Au, Ag, Pt, Cu, GC • Different maintenance-free reference electrodes • Very fast start-up without long conditioning times •...

Direct current amperometry: DC mode The most well-known method of amperometric measurement is direct current amperometry, which is also known as DC mode. It is used primarily to determine in­­ or­­ ganic anions, but can also be used to determine or­­ ga­ nic substances such as phenols or catecholamines. When a constant working potential is applied between the working electrode and the reference electrode, the analytes are, for example, oxidized. Depending on their con­ c ­ entration, a current flows to the auxiliary electrode, which provides the measurement signal. In DC mode it is possible to...

Pulsed amperometry: PAD mode Pulsed amperometry is used when analytes form a de­­ posit on the surface of the working electrode as a result of the electrochemical reaction, making detection in DC mode impossible. In PAD mode, a constant working po­­ tential is applied at the beginning. However, unlike in DC amperometry, the surface of the working electrode is then cleaned continuously through the application of cleaning potentials. A total of up to 40 different potentials can be app­ied for this «potential wave». In this way, l the application can be optimized, so there is always a fresh working...

Flexible integrated pulsed amperometry: flexIPAD mode In flexIPAD mode the focus is entirely on flexibility. This enables a potential-time pattern to be preset at will. Up to 40 constant potentials (steps) and linear potential changes (ramps) can be combined. Whatever the requirements of the application are, they can be fulfilled in this working mode. The range over which the measurement signal is to be integrated can be defined at the user’s dis­­­­ cretion. Either charge or current can be chosen as the mea­­ surement signal. The fast switches of the amperometric detector enable the potential...

Cyclic voltammography: CV mode 07 The method development for determining unknown ana­­ lytes is complex, especially when work is done using PAD or flexIPAD mode. CV mode helps the user to meet this challenge. Through interpretation of a cyclic voltammogram it is possible to arrive at the optimum working potential for the particular application. The cyclic voltammogram also shows the potentials with which the surface of the working electrode can be oxidized and re­­ duced, in order to achieve continuous cleaning. In this way the optimum potential profile for each analyte can be discovered. In...

Intelligent measuring cells as the key to success 08 Intelligent IC stands for self-monitoring measuring systems, minimization of operating errors, and traceability of the measurement results from sample preparation, through separation and on to detection. In practice, that means reliable and simple operation. The intelligent mea­ ­ s uring cells of the amperometric detector are a perfect example. The systems offer the following advantages: • Automatic recognition of the cells in the system • Traceability of data to the measuring cell used • Monitoring of the working and reference electrodes...

The right system for every challenge Metrohm offers the amperometric detector in the form of a detector block (IC Amperometric Detector) and as a stand-alone detector (945 Professional Detector Vario). These two instruments can be used both with 940 Pro­ fessional IC Vario or with 930 Compact IC Flex. De­­ pend­ ing on the task at hand, measurement can be performed in series or in parallel with other analytical channels. Sys­­ tem configurations with gra­­­­ dient elution, with inline eluent preparation, with mi­­ bore columns, and inline cro­ sample preparation techniques (MISP) are also possible....

Technical information 10 Design Type of detector Detection modes Potential range Potential profile Data output channels Digital signal range Electronic noise Control, data collection, and data evaluation 945 Professional Detector Vario – IC Amperometric Detector Amperometry 2.850.9110 2.945.0020 Detector block Stand-alone detector Microprocessor-controlled digital signal processing DC, PAD, flexIPAD, CV -5.0 to +5.0 V in 0.001 V steps DC mode: 1 potential PAD mode: 40 potentials flexIPAD mode: 40 potentials (steps and ramps) Current and charge DC mode: 0.00012 pA to 2 mA, autorange PAD mode:...

Ordering information Detectors 2.850.9110 IC Amperometric Detector 2.945.0010 945 Professional Detector Vario – Conductivity 2.945.0020 945 Professional Detector Vario – Amperometry 2.945.0030 945 Professional Detector Vario – Conductivity & Amperometry 6.5337.000 6.5337.010 6.5337.020 6.5337.030 6.5337.200 Equipment with intelligent cell, 25 and 50 µm spacers and accessories IC equipment wall-jet cell IC equipment wall-jet cell for carbohydrate analysis* IC equipment wall-jet cell for cyanide analysis** IC equipment wall-jet cell for anion analysis*** IC equipment thin-layer cell Cells and electrodes...