Concentration efficiency

Flow Rata Ratio Concentration Concentration Efficiency... 

Therefore, it may be difficult to obtain highly concentrated metal ions in an extremely small volume of effluent such as under-mL-order, even if a small-bore column was used with higher concentration efficiency. 

Figure 14.8 Dependence of the apparent column efficiency on the concentration. Efficiency derived from self-sharpening fronts obtained in staircase frontal analysis of (-)-Trdger s base, 1 at 50°C 2 at 40°C 3 at 30°C and of (+)-Tr6ger s base at 30°C. Reproduced with permission from A. Seidel-Mor-genstem, S.C. Jacobson and G. Guiochon, J. Chromatogr., 637 (1993) 19 (Fig. 6)...

Zhou, S. W., Malaiyandi, M. and Benoit, F. M. 1990. An investigation on the concentration efficiencies of some macroreticular and ambersorb resins using radio-labeled organic contaminants commonly encountered in water, J. Environ. Anal. Chem.,3. 439 71. 

Figure i. Influence of selective ion incorporation on the freeT concentration efficiency of metal cations... 

High total (aqueous + organic phase) flow-rates permissible, leading to increa.sed sample throughputs and concentration efficiencies (C ). 

Despite the great potentials of using FI liquid-liquid extraction for achieving analyte preconcentrations for flame AAS. the number of applications are surprisingly few compared to sorption column preconcentration procedures. The performance of some published procedures 114,38,39] are shown in Table 3.2. Despite the additional enhancement effects from the organic solvents, the concentration efficiencies and consumptive indices generally tend to be inferior to those achievable by sorption procedures (cf. Sec. 

EF and C . enrichment factors and concentration efficiencies including organic solvent enhancement effects. 

In on-line elution, the kinetic features of the process are much more important than for off-line batch procedures. Weak eluents requiring long equilibrium periods may be used successfully for off-line procedures, but caimot be used for on-line applications, since slow elutions may significantly degrade the enrichment factors and/or the concentration efficiencies. 

Although applications for column separation or preconcentration systems coupled to chemiluminescence determinations are few, published reports show no particular difficulties in such applications, except for the requirement of an adjustment of the chemical conditions of the eluate to suit the chemiluminescence reaction. Interferences due to refractive index effects are not likely to occur, owing to the often used spiral shape of the chemiluminescence flow-cell and to the fact that light emission is measured perpendicular to the direction of the flow. Therefore, column washing is usually not as important as for spectrophotometric applications, so that time-based sample loading manifolds such as those used for flame AAS may be used to advantage for improving the concentration, efficiencies. 

Influence of Inhibitor Concentration Efficient corrosion inhibition requires that the inhihitor concentration in the solution exceeds a critical limit, which depends on the environmental conditions. This is illustrated in Fig. 4 for several anodic inhibitors [6]. Below this critical concentration the protection is only partial or, as in the case of carbonate, phosphate, silicate, or tungstenate, the corrosion is even enhanced (see Sect. 5.2.1.2.3). It should be noted that not only underdosing but also overdosing of the inhibitor may in some cases have adverse effects on the inhibition efficiency, for example, due to... 

In an inertial microfiuidic device, concentration, efficiency, and purity are the most broadly used parameters to quantitatively characterize device performance. For this, it is necessary to know concentration of separated particles at each outlet. The most common approach is to collect samples fi om each outlet and then to use flow cytometry to count and size particles. An alternative approach is to use a hemocytometer for direct measurement of particle concentration in each outlet. While hemocytometers offer a low-cost option, the increased error rate (as high as 10 %) will require a larger sample size to maintain the confidence interval. Once particle counts in each outlet are known, purity and efficiency of the separation can be calculated. Purity is calculated as the number of target particles over total particles in one outlet. Efficiency is calculated as the number of target particles from one outlet over total number of target particles from all outlets. Next, the modulated aspect-ratio device is used as an example to demonstrate these calculations. 

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