Mobile phase ion chromatography

Peroxodisulphate salts in air Lab method using mobile phase ion chromatography 79... 

Although the ionic strength of the eluant may remain the same throughout the run, the background conductivity can decrease due to the changing dielectric constant. These baseline changes can be compensated either by chemical means or by computer baseline subtraction. Often, mobile phase ion chromatography is used to elute ions which are very... 

C. Pohl, Mobile Phase Ion Chromatography (MPIC). Theory and Separation." Dionex Dept, of Research Development, IC-Exchange No. 2 (1982). 

Gold cyanide complexes are important in gold-plating baths. As the Au(Ill) bath content increases, the plating efficiency is decreased. Mobile-phase ion chromatography can be used to determine total gold as well as Au(CN)2 and Au(CN)4 [35-37]. An anion-exchange method was also reported [39]. Conductivity or UV detection can be used. 

Ion interaction chromatography (IIC) (also commonly referred to as ion pair chromatography or mobile phase ion chromatography) involves the use of lipophilic stationary phases (such... 

Ion-pair chromatography is actually quite broad in scope. Chromatographic behavior can be distinctly different when organic ions, rather than inorganic, are to be separated. The precise mechanism has been hotly debated (see Section 9.3), and several names have been applied to this type of separation ion-interaction chromatography (IIC), mobile-phase ion chromatography (MPIC), as well as ion-pair (IPC) chromatography. We find the last name to be simple and descriptive. 

Haney et al [1,2], Waters Associates [3], and Knox et al. [4,5] - to name just a few - found that by adding lipophilic ions such as alkanesulfonic acid or quaternary ammoniiun compoimds to the mobile phase, solute ions of opposite chaise can be separated on a chemically bonded reversed-phase column. The term reversed-phase ion-pair chromatography (RPIPC) has generally been adopted for this technique. The term mobile-phase ion chromatography (MPIC) describes a method that combines the major elements of RPIPC with suppressed conductivity detection. Besides the above-mentioned chemically bonded reversed phases, neutral divinylbenzene resins featuring a high surface area and a weakly polar character are also used as stationary phases. 

Anionic surfactants may be determined by conventional ion chromatography, especially if only one anionic or a simple mixture is present. However, most separations require paired ion chromatography, as described above. One vendor uses the term mobile-phase ion chromatography to describe paired-ion HPLC with a conductivity detector and a system to chemically suppress the baseline conductivity of the mobile phase. A number of variations on this theme have been demonstrated, using either polymer backbone or sihca backbone reversed-phase columns, varying levels of organic solvent in the mobile phase, and either isocratic or gradient elution conditions (3,13-15). 

Mobile-phase ion chromatography, a technique which uses traditional ion chromatography equipment, a nonpolar poly(styrene/divinylbenzene) separation column, a suppressor column, and conductivity detection, is suitable for analysis of cationic surfactants. Dilute perchloric acid in 70 volume percent acetonitrile is used as eluent (13). The separation mechanism is the same as in the reversed-phase HPLC methods discussed above. 

C 4 and C 6 a-olefin sulfonates, demonstration of mobile phase ion chromatography Dionex MPIC-NSl, 4.6 x 250 mm H2O/CH3CN, about 60 40, with the water 0.01 M in NH3 or 0.002 M in tetramethyl- or tetrapropylammonium hydroxide Conductivity 13,14... 

Ci4 alkyltrimethylammonium chloride, Ci4-Cifi alkyldimethylbenzyl-ammonium chlorides, benzethonium chloride assay MPIC-NSl mobile phase ion chromatography column, 4 x 200 mm 70 30 or 75 25 CH3CN/O.OO5 M HCIO4 Conductivity 13 ... 

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