Elution chromatography anion

Dionex Corporation Technical Note. TN19. January 1987. Gradient Elution in Ion Chromatography. Anion Exchange with Conductivity Detection (1987). 

The first successful separations of rare earths by this technique was achieved fifty years ago. Two techniques used in the separation of rare earths are (i) displacement chromatography and (ii) elution chromatography. Commercial ion exchangers involving both cation exchangers and anion exchangers are listed in Table 1.18. 

Ohashi, S. Tsuji, N. Ueno, Y. Takeshita, M. Muto, M. Elution peak positions of linear phosphates in gradient elution chromatography with an anion-exchange resin. J. Chromatogr. 1970, 50, 349. 

A characteristic example in the field of cosmetics is the separation and determination of anionic surfactants in shampoos. The sole sample preparation step required is the dilution of the respective product in de-ionized water and membrane-filtration (0.45 pm) prior to injection. Fig. 8-60 illustrates the gradient elution of anionic surfactants in a commercial shampoo with simultaneous conductometric and UV detection. While the peak pattern with UV detection indicates the presence of alkylbenzene sulfonate (ABS) (see also Fig. 5-40 in Section 5.5), the characteristic peak profile for alkylether sulfate (see Fig. 5-39 in Section 5.5) is also evident in the conductometric chromatogram after visually subtracting the ABS-signal. Therefore, application of ion chromatography provides a way to unequivocally identify surfactant raw materials in finished cosmetic products without the time-consuming sample preparation. 

Elution peak positions of linear phosphates in gradient elution chromatography with an anion-exchange resin. 

In ion chromatography, anions are separated by ion exchange and detected by their electrical conductivity. The conductivity of the electrolyte in the eluent is ordinarily high enough to make it difficult or impossible to detect the conductivity change when analyte ions are eluted. Therefore the key feature of suppressed-ion chromatography is removal of unwanted electrolyte prior to conductivity measurement. 

Figure 10.200 Gradient elution of anionic surfactants in a shampoo using ion-pair chromatography on a polymeric reversed-phase material. Separator column Hypersil 5 MOS eluent (A) 1 mmol/L NaOAc and (B) MeCN ...

Pfrepper et al. [37] verified the equivalence of Eqs. 2 and 3. They compared values for Hf isotopes obtained, first, in batch experiments and by conventional elution chromatography in the anion-exchange system HS36 (a resin with the quaternary triethyl-ammonium group) -0.27 M HF/x M HNO3 (x variable) with, second, values obtained in the same system with the multi-column technique (MCT). They used the short-lived Hf isotopes and detected the daughter... 

Dried shrimp was ground, defatted with benzene, and then extracted with cold water. The luciferase extracted was purified first by a batch adsorption onto DEAE cellulose (elution with 0.4 M NaCl), followed by gel filtration on a column of Sephadex G-150, anion-exchange chromatography on a column of DEAE-cellulose (gradient elution 0.05-0.5 M NaCl), and gel filtration on a column of Ultrogel AcA 34. The specific activity of the purified luciferase was 1.7 x 1015 photons s 1 mg-1, and the yield in terms of luciferase activity was about 28%. 

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