Pulse-amperometric detection system

Oligosaccharides were isolated preparatively by high-pH anion exchange chromatography carried out on a LC-system (Dionex Corporation, Sunnyvale CA) equipped with a CarboPac PA-1 column (9 x 250 mm), coupled to a Spectra System AS 3500 auto sampler. The detection was carried out using Pulsed Amperometric Detection (PAD-II). 

S. Sawada, H. Torii, T. Osakai, and T. Kimoto, Pulse amperometric detection of lithium in artificial serum using a flow injection system with a liquid/liquid-type ion-selective electrode. Anal. Chem. 70, 4286-4290 (1998). 

The quality of this library was examined by monosaccharide compositional analysis. A portion of the trisaccharide library was treated with aqueous trifluroacetic acid at 100°C for 4 h. Analysis of the resulting mixture of monosaccharides on a Dionex HPLC system with a PA1 column and pulsed amperometric detection (PAD) showed that galactose, glucose, and mannose were present in approximately the required ratio. 

Changes in bioengineered expression systems can alter the number and composition of carbohydrate residues attached to recombinant or monoclonal antibody products [301]. The use of high pH anion-exchange HPLC and pulsed amperometric detection (Dionex Corp) has enabled the analytical profiling or mapping of the characteristic biantennary carbohydrate structures following their enzymatic release from both murine and humanized monoclonal antibodies [302]. 

J. A. Polta and D. C. Johnson, Pulsed Amperometric Detection of Elec-troinactive Adsorbates at Platinum Electrodes in a Flow Injection System. Anal. Chem., 57 (1985) 1373. 

In high performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD) system, anion exchange column is used for CD separation. CarboPac PA-10 and 100 are all selected for CD qualitative analysis. The main eluent for the column of CarboPac PA-100 is sodium hydroxide, the gradient eluent is sodium acetate. 

Pulsing the applied potential at the working electrode using simple waveforms has long been employed in EC analysis and was also proposed in some of the earliest patents for EC detectors for liquid chromatography. In the early 1980s, Johnson and co-workers at Iowa State University began an extensive series of studies on pulsed amperometric detection at platinum electrodes in a flow injection system of simple... 

LaCourse and Owens [26] showed the superiority of integrated amperometry over conventional pulsed amperometric detection in their work on organic sulfur compounds under reversed-phase conditions. Pulsed amperometry allows direct detection of thio-redox systems (-SH/-S-S-), provided they carry a pair of free electrons at the sulfur atom. As an illustration, the chromatogram in Figure 8.18 displays the separation of lipoic acid, which carries a disulfide bridge as a structural element... 

H.p.l.c. on pellicular anion exchange packings with a strongly alkaline eluant and pulsed-amperometric detection (the Dionex system) has gained sufficient prominence to be given its own abbreviation (HPAEC), which is used herein. 

Medeiros, R. A., B. C. Lourengao, R. C. Rocha-Filho et al. 2010. Simple flow injection analysis system for simultaneous determination of phenolic antioxidants with multiple pulse amperometric detection at a boron-doped diamond electrode. Anal. Chem. 82 8658-8663. 

A reliable simultaneous reversed-phase h.p.l.c. assay for ascorbic acid and dehydroascorbic acid in biological systems utilized sequential elecmx hemical and u.v. detection. The determination of these acids in dairy foods was achieved by derivatization with 4-methoxy- or 4-ethoxy-1,2-phenylenediamine to form quinoxaline derivatives, reversed-phase chromatography and fluorescence detection. Detection limits were 50 and 70 fmol per 5 pi injection, respectively. Simultaneous determination of ascorbic acid and sulphite in beer was achieved using a strong acid resin colunui, acid eluant, and pulsed amperometric detection. ... 

---