Percent concentration calculation

Since the sensory data collected involved degree of sample difference from a reference, it was felt that the analytical data should be analyzed in a similar manner. In cases where some peaks making up a multicomponent mixture are known to be specific to that mixture, this is a relatively simple matter. In such cases, the peak areas of the known components can be compared to a reference and average percent difference calculated. However, if it is not possible to pick out peaks that are clearly specific to a single multicomponent mixture, a more sophisticated technique such as factor analysis is required. There are circumstances where all peaks are common to each multicomponent mixture, i.e. qualitatively similar but quantitatively different. Also there are cases where peaks are found only in one of the multicomponent mixtures, but it is not clear to which mixture they belong. In these cases factor analysis is required to extract patterns that are characteristic of the specific multicomponent mixtures. Analytical concentrations of each of the multicomponent mixtures are then calculated as a set of factor scores where each score is directly proportional to the actual concentration of each multicomponent mixture. 

In the case of this multicomponent mixture, it was known which peaks belonged to which multicomponent. Therefore peak areas of known components could be easily compared to a reference and the average percent difference calculated. This was done for each sample with a simple program. This program was automatically initiated at the time a sample was chromatographed by the HP3354 LAS. An example of the output is shown in Table I. This sample was formulated to contain -100% (or 0%) of a multicomponent C and -50% (or 1/2) the normal concentration of a multicomponent A. From the list of missing peaks and the fraction of individual peaks, this was found to be true. The extra peaks which are listed can be used to pinpoint possible sources of contamination. 

The NTO/TNT formulation is characterized by a lower vulnerability than RDX/ TNT and Composition B. NTO is also used to produce pressed PBXs with thermoplastic binders and cast PBXs with thermosetting binders for IMs. NTO is an explosive with calculated performance near that of RDX but with insensitivity approaching that of TATB. Possible use of NTO is as an alternative to RDX in formulations where a lower sensitivity is desired or as an alternative to TATB where better performance is required without a large increase in sensitivity [123, 152, 153, 215]. The formulations based on NTO/binder (FPC-461, Viton-A, Kel-F800, Estane-5702 and Kraton G) in 95/5 (mass percent concentrations) have also been tested for compatibility and none of the NTO/binder formulations showed evidence of incompatibility. 

H 0. N , and CO ore similarly calculated. Intensities may be converted to percent concentration hv dividing by the component s sensitivity and normalizing in 100. The formulae for these calculations are therefore ... 

The concentration calculated above is on the sample "as is" and not as dry weight corrected. Concentration on a dry weight basis may be calculated by dividing the above result with the percent total sohd expressed in decimal. 

The confirmation of a compound s identity is only one half of the overall confirmation procedure quantitative confirmation is the other half. Compound concentrations calculated from analyses on two columns or two detectors must be in agreement. The EPA recommends a 40 percent difference (calculated as the RPD shown in Equation 1, Table 2.2) as a threshold value for making decisions on the presence or absence of a compound (EPA, 1996a). This means that the concentrations obtained from two columns or two detectors that agree within 40 percent indicate the presence of an analyte, provided that the retention time confirmation criterion has been also met. 

Average the two normalities. Using the molecular weight of 60 g/mole for acetic acid, calculate the percent concentration of acetic acid in vinegar. 

Mix each aliquot collected with an equal volume of hexane, and transfer to a separatory funnel. Extract this mixture with three 15-mL aliquots of water combine the water extracts, and calculate the percent concentration (P) of the monosulfonated derivative (a = 0.0513 mg/L/cm at 615 nm) and the isomeric derivative (a = 0.0478 mg/L/cm at 610 nm) by the equation... 

Assume that the reaction rates are both first-order in ethanol and that no products are initially present. After 100 s in a constant volume system, there is 30 percent of the ethanol remaining and the mixture contains 13.7 percent ethylene and 27.4 percent acetaldehyde. Calculate the rate constants and 2-Compound A is converted to B in a CSTR. The reaction rate is first-order with a reaction rate constant of 20 min. Compound A enters the reactor at a flow rate of 12 m /min (concentration of 2.0 kmol/m ). The value of the product B is 1.50 per kmol and the cost of reactor operation is 2.50 per minute per cubic meter. It is not economical to separate unconverted A to recycle it back to the feed. Find the maximum profit. 

Fig. 2.7 Lipophilic IsoK/LG scavengers protect against cytotoxicity induced by oxidative stress. HepG2 cells were incubated with vehicle, pyridoxamine, pentyl-pyridoxamine, or salicylamine for 30 min prior to treatment with various concentrations of hydrogen peroxide (Davies et al., 2006). Viability was determined by detection of ATP using ATPlite luminescence assay and percent viability calculated relative to untreated cells (Mean SEM n = 8)...

Actually, in most cases, a correction is not necessary because the error resulting from the buoyancy will cancel out in percent composition calculations. The same error will occur in the numerator (as the concentration of a standard solution or weight of a gravimetric precipitate) and in the denominator (as the weight of the sample). Of course, all weighings must be made with the materials in the same type of container (same density) to keep the error constant. 

Obtain an unknown mixture of meta and para isomers from your instructor. Prepare a mixture of this with o-xylene by adding 70 parts of the unknown to 30 parts o-xylene. Run the spectrum on this mixture and, using the baseline method and the same peaks as before, measure Pq/P for the three compounds and calculate log(Po/F)/log(Po/F)ortho for the two unknown isomers. Compare with the calibration curve to determine the percent concentrations of the meta and para isomers use the spreadsheet for calculations. Remember to divide by 0.7 to convert to initial concentrations. 

On the basis of this assumption, the authors studied the equilibrium concentrations of all eight of these aldoses at three total concentrations (0.10, 0.25, and 0.5 M) and at three pH values (6.5, 7.0, and 7.5), and calculated the percent concentrations of the reducible forms. On the basis of the data obtained on the presumed concentrations of the acyclic forms, a relationship between their stability and structure was sought. Although their interpretation of the data was incorrect (because the polarographic waves do not have diffusion character in these cases), the data nevertheless provided qualitative information as to the stability of the cyclic forms of the aldoses studied, as may be seen from a comparison of the order of aldose stability obtained in this work with the values obtained later (see Table II p. 143). 

A spark discharge is produced between the flat surface of a chill-cast aluminum sample and the tip of a pointed graphite counter electrode. The emission intensities for 31 different spectral lines and an aluminum internal-reference line are measured simultaneously by 32 photomultiplier tubes positioned behind exit slits. At the end of the 10-15 sec exposure period, the accumulated capacitor potentials for each analytical line relative to the potential for the aluminum internal reference line are automatically measured and recorded. The unknown values are calculated automatically in terms of percent concentration. 

Animals were predosed as described above. These results are the mean percent inhibition calculated with 14 animals in each control group and 8 at each test variable. Drug was given orally in 1 ml vehicle 122. The oral doses were chosen to illustrate both tachyphylactic concentration (25 mg/kg) and nontachyphylactic dose (0.01 mg/kg). A 2 hr time interval was used between prinary and secondary dose. 

Strictly speaking, of course, renal accumulation or metabolism of a plasma solute also constitutes renal clearance from plasma. Thus, the kidney readily filters plasma Cd-metallothionein but almost completely reabsorbs it at low concentrations little is excreted in urine [16], and the reabsorbed protein is not returned to blood. A more general expression for renal clearance from plasma clearance in ml/min is therefore given by fhe producf of renal plasma flow (RPF) and E, the percent extraction calculated as (A-V)/A, where A and V represent the arterial and venous plasma concentrations of the solute under study. Note that the simplifying assumption is implicitly made that solute fluxes between red cells and plasma do not affect A or V. The general formula for clearance is thus... 

It is necessary to change the weight percent concentration to volume percent in order to calculate the cake and filtrate volumes. One kilogram of su ension at 10 wt% soMs contains 0.1 kg of solids and 0.9 kg of liquid. The volume of the suspension is ... 

Three different percent concentrations for solutions are used. A weight/weight percent (abbreviated w/w) is the mass of solute contained in 100 mass units of solution. Thus, a 12.0% (w/w) sugar solution contains 12.0 grams of sugar in each 100 g of solution. In terms of this concentration, the general formula for percent calculations becomes... 

A more commonly used percent concentration is we t rolume percent (abbreviated w/v), which is the grams of solute contained in 100 mL of solution. In these units, a 12.0% (w/v) sugar solution would contain 12.0 g of sugar in each 100 mL of solution. This percent concentration is normally used when the solute is a solid and the solvent and resulting solutions are liquids. The general formula for the calculation of percent concentrations in these units is... 

In a process for concentrating 1000 kg/min of freshly extracted orange juice containing 12.5 wt percent solids, the juice is strained, yielding 800 kg/min of strained juice and 200 kg/min of pulpy juice. The strmned juice is concentrated in a vacuum evaporator to give an evaporated juice of 58 percent solids. The 200 kg/min of pulpy juice is bypassed around the evaporator and mixed with the evaporated juice in a mixer to improve the flavor. This final concentrated juice contains 42 wt percent solids. Calculate the concentration of solids in the strained juice, the flow rate of the final concentrated juice, and the concentration of the solids in the pulpy juice bypassed. 

The surface material was removed by Ar bombardment. The sputtering rates are determined from known thickness of Ta205 films. Since the sputtering rate of this material relative to Ta205 is unknown, the absolute depths are approximate. The relative atomic percents are calculated by using experimental sensitivity factors and peak areas for each of the elements shown. The relative atomic concentrations show reproducibility to 0.2% and are correct to within 5% of the absolute concentrations. 

To calculate mass percent concentration, divide the mass of the solute by the mass of the solution (solute and solvent) and multiply by 100%. 

Strategy Use the molar mass of glucose to determine the number of moles of glucose in a liter of solution. Use the density Un g/L) to calculate the mass of a liter of solution. Subtract the mass of glucose from the mass of solution to determine the mass of water. Use Equation 13.1 to determine the molality. Knowing the mass of glucose and the total mass of solution in a liter, use Equation 13.2 to calculate the percent concentration by mass. 

Calculation of Weight/Volume Percent Concentration and Molarity... 

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