Split-peak method

Injection of the protein sample (antigen or antibody). In frontal analysis the sample is applied continuously to the column by switching to the eluent containing the protein at the desired concentration. With the split-peak method, small pulses are repeatedly injected into the column. 

The present method recommended by this major industrial account is to disconnect the center-voided column, grasp it in one hand, and rap the counter with it twice, reverse the column, and do the same with the other end. Obviously, not hard enough to bend the column Hook it up backwards and run it at high flow rate for a minute or two. Then run the four-standard mixture. The column is run reversed from then on. It is possible that an end void may be formed yielding rabbit-eared split peaks, and must be repacked, but the column bed should be restored. 

Several theoretical models were constructed to describe the chromatographic process in the frontal 116.191 and the zonal elution mode 20. The conventional method of obtaining the kinetic parameters consists in fitting the model to the experimental breakthrough curves. Another method based on the split-peak effect is a direct measurement of the apparent association rate constant (7,211. Because of the slow adsorption process, a fraction of the solute injected as a pulse into the immunochromatographic column is eluted as a nonretained peak. This behavior is observed at high flow rates, with very short or low-capacity columns 121—251. 

On the basis of the split-peak equations, Hage et al. I8) developed a model to interpret competitive binding immunoassays and applied the method to the determination of low levels of albumin in urine 47). An equation was derived to predict the assay response as a function of flow rate, amounts of analyte and... 

Enzymatic digestion of proteins in 1 1 0/ 0 water has been applied to facilitate de novo sequencing [136]. The labelling results in split peaks with a 2 Da difference for the y-ions, enabling easy discrimination between peaks due to b- and y-ions. Other stable isotope labelling methods (Ch. 18.4.2) involving modification of either the N- or the C-terminal can assist in de novo sequencing as well. 

Fig. 20.2 shows the NMR spectra for the PVA in (A) the solution (B-D) gel and (E) solid states as measured by solution and solid-state NMR methods [16]. The NMR spectrum for the PVA aqueous solution obtained by the solution C NMR method (Fig. 20.2(A)) shows each of the signals for the CH and CH2 carbons split into multiple peaks due to its stereochemical configuration. The triply split peaks for the CH carbon are assigned to the mm, mr and rr triads from high frequency [17-19] and, furthermore, each of the triad peaks splits into pentad peaks. The split peaks for the CH2 carbon come from tetrad tacticity. In the solution NMR spectrum for the PVA gel shown in Fig. 20.2(B), the signal for the CH carbon splits into three peaks due to triad tacticity. The signals for the CH and CH2 carbon become broader as compared with those for the PVA solution. This is caused by the...

In the split/pool method of combinatorial synthesis, mixtures of compounds are made that are difficult to characterize. The LC/CLND of a nominally equimolar pool (based on nitrogen) should yield equal-sized chromatographic peaks of compounds. In the early stages of a lead development project, weighable quantities of authentic pure samples of a compound are not available, and yet quantitative measurements such as IC50, solubility, or plasma stability need to be made. LC/CLND can be used to calibrate solutions made from submilligram synthetic samples. LC/CLND is an important new technique to add to the arsenal of the organic analytical laboratory. 

SWV was used to perform a full thermodynamic and kinetics characterization of the BU surface redox couple. Therefore, from the combination of the quasi-reversible maximum and the splitting of the net square wave voltammetric peak methods, values of (0.386 + 0.003) V, (0.46 0.04), and 2.7 x 10 s were calculated for the formal potential, the anodic transfer coefficient, and the formal rate constant, respectively, of the BU overall surface redox process in pH 4.00 citrate buffer solutions. 

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