Chromatography conductivity suppression

Nowak, M. and Seubert, A., Application of experimental design for the characterization of a novel elution system for high capacity anion chromatography with suppressed conductivity detection, /. Chromatogr. A, 855, 91,1999. 

Determination of Perchlorate in Drinking Water by Ion Chromatography with Suppressed Conductivity and... 

Wagner P, Pepich BV, Pohl C, Srinivasan K, De Borba B, Lin R, Munch DJ (2009) EPA Method 302.0. Determination of bromate in drinking water using two-dimensional ion chromatography with suppressed conductivity detection. U.S. EPA, Cincinnati, OH, Available at http //water.epa.gOv/scitech/drinkingwaterAabcert/upload/met302 0.pdf... 

Fig.l The effect of the background conductivity suppression on the monitored signal of the analyte anions, after separation by means of ion chromatography. Peaks 1 = fluoride, 2 = nitrate, 3 = sulfate. 

This is the classical ion chromatography detector and measures the eluate conductivity, which is proportional to ionic sample concentration (provided that the cell is suitably constructed). Its sensitivity decreases as the specific conductivity of the mobile phase increases. The active cell volume of 2 gl is very small. Good conductivity detectors have automatic temperature compensation (conductivity is highly temperature-dependent) and electronic background conductivity suppression. The linear range is not large. 

Modern methods of chemical conductivity suppression utilize much smaller and more efficient devices than the original stripper columns, but the basic principles are largely unchanged. The reactions for suppressed anion chromatography are as follows ... 

Ion chromatography with suppressed conductivity detection has been extremely successful in filling a large gap that previously existed in inorganic analysis. However, the necessity for a suppressor device does add to the complexity of the instrumentation. It also restricts the type of eluent that can be used and to some extent limits the separating ability of the method. 

Although a very large number of organic anions may be separated by ion chromatography, non-suppressed conductance is not always a viable detection method. Anions of small organic acids can usually be detected but the conductivity of more... 

Chloride -1 5 soilAvater extract, ion chromatography (chemical suppression of eluent conductivity)... 

Determination of polyphosphates using ion chromatography with suppressed conductivity detection. Application Note 71, Dionex, Sunnyvale, CA, USA, 2002. 

De Borba, B.M. Rohrer, J.S. Determination of biogenic amines in alcohohc beverages by ion chromatography with suppressed conductivity detection and integrated pulsed amperometric detection. J. Chromatogr. A, 2007,1155,22-30. 

Ion-exchange is the primary separation mode used with modern ion chromatography, although other approaches used for separation of inorganic anions and cations include ion interaction, ion exclusion, and chelation chromatography. Ion chromatography, with suppressed conductivity detection, is the most widely used and generally offers the best performance. 

The mobile phase used for anion chromatography with suppressed conductivity detection must (i) have adequate strength for elution of sample anions and (ii) produce products with very low conductivity after passing through the suppressor unit. 

US EPA (2005) Method 332.0 Determination of Perchlorate in Drinking Water by Ion Chromatography with Suppressed Conductivity and Electrospray Ionization Mass Spectrometry. US Environmental Protection Agency, Cincinnati, OH, USA. 

Figure 10.234 Separation of iodide in miik powder using anion-exchange chromatography and suppressed conductivity detection after in-iine diaiysis. Separator coiumn Metro-sep A Supp 5 column dimensions 150 mm X4 mm i.d. eluent 3.2 mmol/L Na2C03 -l-1...

Cation-exchange chromatography with suppressed conductivity detection can also be applied to the analysis of aliphatic quaternary ammonium compounds. Typical examples are carbachol (2-[(aminocarbonyl)oxy] A/,A/,A/-trimethyletha-naminium chloride) and bethanechol (2-[(aminocarbonyl)oxy]-A/ iV,A/-trimethyl-propan-l-aminium chloride). 

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