Chromatography measurement

I mmobili zed-artifidal-membrane chromatography measurements of membrane partition coeffident and predicting drug membrane permeability. /. Chromatogr. A. 1996, 728,113-128. 

Ong, S. Liu, H. Pidgeon, C., Immobilized-artificial-membrane chromatography Measurements of membrane partition coefficient and predicting drug membrane permeability, J. Chromatogr. A 728, 113-128 (1996). 

When performing size exclusion chromatography measurements, do the large polymer molecules or small polymer molecules elute from the column first Why ... 

Percentage expresses HPLC recovery of 2-bromo-4,6-dinitroaniline (BDNA). Additional thin layer chromatography measurements indicate anaerobic transformation BDNA... 

The major factor influencing the thermal and mechanical properties is the composition differences between the polymers. Gel permeation chromatography measurements have shown that the molecular weight averages and molecular weight distributions are not significantly different for the samples which have been studied and are therefore not seen as important as far as Tg and mechanical measurements are concerned. 

The calibration standards included sodium form polystyrene sulfonates obtained from Pressure Chemical Co., Pittsburgh, Pa., and sodium toluene sulfonate. Measurements were taken at 0.5 to I.Oml/mln flow rates. The logarithm of the molecular weight of the standards was linear it suggests a framework for approaching an interpretion of the structure of the scission products. This application of size exclusion chromatography measurements must be viewed as a first approximation because of the unmeasured differences between the chromatographic behavior of the linear standards and the expected branched structure of the scission products. 

The coefficient of determination, R, of the RON model is 0.84 for both catalysts. Figure 12.12a and b shows RON predicted from H-NMR versus RON calculated from gas chromatography measurements for catalysts A and B. The uniform spread of the data points suggests that H-NMR does not provide necessary information to accurately predict gasoline quality. 

The presence of cross-associated species needs to be considered in the interpretation of copolymerization kinetics. It has been found 269) that the reaction of poly(butadie-nyl)lithium with p-divinylbenzene in benzene solution proceeds at a rate which increases markedly with time. Such a result implies that the poly(butadienyl)lithium aggregate is less reactive than the mixed aggregate formed between the butadienyl-and vinylbenzyllithium active centers. Interestingly, no accelerations with increasing reaction time were found with poly(butadienyl)lithium and m-divinylbenzene nor with poly(isoprenyl)lithium and either the m- or p-divinylbenzenes. This general behavior was subsequently verified 270) by a series of size exclusion chromatography measurements on polydiene stars (linked via divinylbenzene) as a function of conversion. 

Simulated by chromatography Measured at other hours but at these conditions... 

C, elution chromatography, measured range 10-30°C, Schwarz Miller 1980)... 

Oster, H. Reversions gas chromatography, measuring technique and application. Z. Anal. Chem. 247, 257 (1969). 

The experimental error is also relevant to data treatment, and will also be considered in this section. The extent of the analytic error depends on various factors including the type of methodology adopted, operator training, and inoculum protocols. The errors are relatively high in biological systems for example, 10-30% for proteins concentration 7-10% for cells concentration and viability (especially at low viability) 2-5% for liquid chromatography measures (glucose, lactate, amino acids) (Portner and Schafer, 1996 Miller and Reddy, 1998). 

Tsitsilianis et al. [14] also reached the conclusion, from size exclusion chromatography measurements, that AnBn type copolymers, where A is PS and B is poly(ferf-butyl acrylate), are more expanded than the corresponding homostars, due to the increased density of two different kinds of segments which leads... 

COMPENDIUM OF THE ANALYSIS OF Hg SPECIES SAMPLE PROCEDURES, PREPARATION, CHROMATOGRAPHY, MEASUREMENT, AND DETECTION... 

Tognacci et al. [ 183] discussed various methods for measuring the monomer concentration in the polymer particles. The method proposed by the authors is a direct estimation of the solvent activity by the GC (gas chromatography) measurement of its partial pressure in the gas phase at equilibrium with the polymer particle, monomer droplet (if any) and aqueous phase in the latex. They proposed an original measuring technique and carried out measurements for different monomers (St, MMA, and VAc) and polymeric matrices (PSt and MMA-VAc copolymer), both above and below saturation conditions (corresponding to Intervals II and III). They compared the experimental data with that predicted by the monomer partitioning relationships derived by Maxwell et al. [166,170] and Noel et al. [172]. 

Load a small volume of a probe compound (e.g. toluene in reversed-pha.se chromatography). Measure plate count of Gaussian peak. 

Because MALS determinations are independent of the separation mechanism, they may be applied to many types of HPLC. Reversed-phase separations are of particular significance because they cannot be calibrated, as sequential elutions do not occur in a monotonic or otherwise predictable manner. Again, as with all MALS chromatography measurements, all that is required is that the concentration and MALS s signals be available at each elution volume (slice). 

Matsuhashi, S., Yokohiki, K. and Hatanaka, C. 1989. High performance liquid chromatography measurement of the degradation limits of pectate by cxopcclinascs, Agric. Biol. Chem., 53(5) 1417-1418. 

UV-visible spectra were obtained using a Cary 118C spectrophotometer. Insertion probe mass spectra were obtained with a Dupont 21-49IB mass spectrometer, the FAB spectra with a VG MM-ZAB instrument, and the FD spectra with a JEOL DX-300 mass spectrometer. High pressure liquid chromatography measurements were made with a Waters instrument fitted with dual channel (405 and 546 nm) optical detection and using C18 analytical and semipreparative columns. 

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