Molecular retention

Symbol Retention Molecular weight Chonical shifts for protons time (sec) Calc. Found... 

Proposed structure Relative retention Molecular mass Ri R2 R3... 

Compound Symbol Retention Molecular weight Chemical shifts for protonsb... 

Sahoo, S.K. and Labhasetwar, V., 2005. Enhanced antiproliferative activity of transferrin-conjugated paclitaxel-loaded nanoparticles is mediated via sustained intracellular drug retention. Molecular Pharmaceutics, 2(5), 373-383. 

The calculated molecular interaction energy values between the model phase and the analytes are summarized in Table 3 of the Appendix (p. 287). The main retention (molecular interaction) forces were van der Waals forces. The correlation between the log k values and the molecular interaction energy values (MIVW) was closed to 1. The order of the MIVW values was Als > OHs > allg lbenzenes (AlBZs) > PMBZs > PCBZs st PAHs, as seen in Figure 4.13. The behavior of PCBZs indicated that their MIVWs were similar to those of PAHs, and those of PMBZs were similar to those of AlBZs, as shown in Figure 4.13 where experimental data measured at 200 °C is presented. 

Compound name Retention Molecular formula Molecular ... 

Retention Molecular Formula [M] Avocado Samples Containing the... 

It is important to realize that many important processes, such as retention times in a given chromatographic column, are not just a simple aspect of a molecule. These are actually statistical averages of all possible interactions of that molecule and another. These sorts of processes can only be modeled on a molecular level by obtaining many results and then using a statistical distribution of those results. In some cases, group additivities or QSPR methods may be substituted. 

In a chromatographic analysis of low-molecular-weight acids, butyric acid elutes with a retention time of 7.63 min. The column s void time is 0.31 min. Calculate the capacity factor for butyric acid. 

In the same chromatographic analysis for low-molecular-weight acids considered in Example 12.2, the retention time for isobutyric acid is 5.98 min. What is the selectivity factor for isobutyric acid and butyric acid ... 

To use GPC for molecular weight determination, we must measure the volume of solvent that passes through the column before a polymer of particular molecular weight is eluted. This quantity is called the retention volume Vj. Figure 9.14 shows schematically the relationship between M and Vj it is an... 

Three polystyrene samples of narrow molecular weight distribution were investigatedf for their retention in GPC columns in which the average particle size of the packing was varied. In all instances the peaks were well resolved. The following results were obtained ... 

The protonated form of poly(vinyl amine) (PVAm—HCl) has two advantages over many cationic polymers high cationic charge densities are possible and the pendent primary amines have high reactivity. It has been appHed in water treatment, paper making, and textiles (qv). The protonated forms modified with low molecular weight aldehydes are usehil as fines and filler retention agents and are in use with recycled fibers. As with all new products, unexpected appHcations, such as in clear antiperspirants, have been found. It is usehil in many metal complexation appHcations (49). 

Hydrophobic interactions and trapping of molecules in a molecular sieve formed by humic materials have been hypothesized as retention mechanisms for prometryn. It has been shown that fluridone, fluazifop, and bipyridyhum herbicides penetrate into interlamellar spaces of smectites and can become trapped. 

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