Injection amount

Injected amount (ng) Observed response (counts) Calculated response (counts) Deviation between observed and calculated response (%) ... 

Quantitation is performed by the calibration technique. A new calibration curve with anilide standard solutions is constructed for each set of analyses. The peak area or peak height is plotted against the injected amount of anilide. The injection volume (2 pL) should be kept constant as the peak area or peak height varies with the injection volume. Before each set of measurements, the GC or HPLC system should be calibrated by injection of standard solutions containing about 0.05-2 ng of anilide. Recommendation after constructing the calibration curve in advance, standard solutions and sample solutions are injected alternately for measurement of actual samples. 

Quantitation is performed by the calibration technique. Prepare a calibration curve by injecting pyrithiobac-methyl standard solutions, equivalent to 0.2,0.5,1.0,2.0,3.0 and 4.0 ng, into the gas chromatograph. Measure the heights of the peaks obtained. Plot the peak heights in millimeters against the injected amounts of pyrithiobac-methyl in nanograms. 

Quantification is performed by the calibration technique. Construct a new calibration curve with acetamiprid standard solutions using acetone for each set of analyses. Inject 2- uL aliquots of the standard solution containing acetamiprid from 0.04 to 1 ng in 2 uL of acetone. The acetamiprid peak usually appears at a retention time around 4 min. Plot the peak height against the injected amount of acetamiprid. 

Inject 1 o.L of each fenothiocarb standard solution into the gas chromatograph. Using log-log paper, plot the peak heights in millimeters against the injected amount of fenothiocarb in nanograms. 

Quantitation is performed by the calibration technique. The calibration curve is constructed with pyrimidifen standard solutions, plotting the peak height against the injected amount of pyrimidifen. 

Injection systems of a capillary gas chromatography should fulfil two essential requirements (i) the injected amount should not overload the column (ii) the width of the injected sample plug should be small compared with band broadening due to the chromatographic separation. Good injection techniques are those which achieve optimum separation efficiency of the column, allow accurate... 

Type of CNTs (injected amount) Animal species Method of administration Exposure duration Toxicity Year/ Reference... 

Injection mode-. Hydrodynamic injection is generally more reproducible than electrokinetic injection. The electrokinetically injected amount has a non-linear relationship with the injection time. °... 

Figure 6.46 LC-NMR chromatogram at 500 MHz from system described in Figure 6.45. Each NMR spectmm represents 12 coadded scans acquired in 12 s. Flow rate, 5 pFmin active volume, 1.11. No solvent suppression scheme was used, and all spectra were acquired with the spectrometer gain set to maximum, (a) Injected amounts 2.3 (26 nmol) 4.8 (20 nmol), and 4.8 pg (21 nmol) of Ala, Gly-Tyr and Phe-Ala (I, II, III), respectively, (b) injected amounts 8 nmol of each component. Extracted NMR spectra shown in (c) Ala, (I), (d) Gly-Tyr (II), (e) Phe-Ala (III). Reproduced from [85] with permission. Copyright 1999 American Chemical Society.

Fifteen cases of bone tumors resulting from intravenous Thorotrast injection have been reported (9 of which were osteosarcoma). The mean latency period was 26 years and the latency period and injected amount of Thorotrast were inversely related (Flarrist et al. 1979). The mean dose rate to bone was 16 rads/year (0.16 Gy/year) per 25 mL of injected Thorotrast (Van Kaick et al. 1983). 

The distribution pattern of intravenously-injected Thorotrast in animals is similar to the pattern in humans most of the Thorotrast is taken up by the RES (Guimaraes et al. 1955 McNeill et al. 1973 Reidel et al. 1979). Reidel et al. (1979) determined that the average percent distribution of Thorotrast in the liver was within one order of magnitude in mice, rats, rabbits, dogs, and humans. The amount of thorium in the spleen of all species, except mice, was clearly below that in humans. Only 50% of the thorium in rats was retained in the liver and spleen, while approximately 85% was retained in humans. Direct comparison of the species is difficult, since the data were taken from other authors and analyzed by Reidel et al. (1979). The study concluded that the biological behavior of colloids was similar in humans and animals. Kaul and Heyder (1972) reported an extremely low rate of clearance of the colloid form from the blood about 1 hour after intravenous injection in rabbits. Subsequently, an increase in the rate of disappearance from the blood of the colloid form (biological half-life of 90 minutes) and of the soluble form (biological half-life of 75 minutes) was found. After 3, 6, or 12 hours, 23, 45, or 60% of the injected amount, respectively, was located in the liver. 

A very small percentage of injected thorium-232 dioxide (Thorotrast) in humans was excreted (more in the feces than urine) (Kaul and Muth 1978 Molla 1975). Jee et al. (1967) found that a patient excreted 0.7% of the injected amount of Thorotrast in the 17 days between injection and the death of the patient (mode of excretion not reported). Kemmer (1979) determined that the amount of thoron (radon-220) exhaled by the lungs in humans correlated to the amount of Thorotrast intravenously injected. The thoron (radon-220) correlated with a "radium-224 equivalent value."... 

Once it was realized that multiple columns in the first SEC really did not offer cmy advantage in terms of greater injection amounts because of increased dilution in the columns, smaller injections and less columns reduced emalysis times 50% with no loss in sensitivity. For the analyses shown in Figure 8, only three columns were used in the first SEC and three in the second. With this system the first analysis by both SBC instruments required a total of 30 minutes and subsequent analyses of the same sample eibout 15 minutes each. However, despite these significant reductions in analysis times in comparison to the initial work, complete analysis of even one complex polymer required many cross fractionations and generated much data. 

An external standardisation method is employed to perform quantitative analysis. In the cited study, calibration curves for each compound are obtained by injecting amounts ranging from 0.08 to 10 nmol. The amount of injected standards is logarithmically proportional to the peak area. 

Quantitative analysis is performed making use of the linearity of the detector response. In fact, peak areas of standards and samples are well correlated with the injected amount, and it is possible to build a calibration curve without the use of an internal standard. 

Chromatography is a well-known analytical method, but is also a validated industrial purification tool. However, the preparahve or produchon approach is very different from the analytical one. In analyhcal chromatography, the focus is on analyzing a mixture in order to separate the peaks of each component. The injected amount is small and peak resolution tends to be maximized. Column size is generally small in order to minimize analyhcal costs. An example of an analytical chromatogram is presented in Figure 12.1. 

For a preparahve applicahon, focus is on recovering the targeted products while ophmizing produchon costs. The object of the separation is to reach the purity and recovery yield required for one or more specific components of the feed mixture. To maximize produchon, injechons are made as often as possible. The amount of stahonary phase used is set in order to minimize the costs of the product, equipment, and eluent consumption. Figure 12.2 presents the preparahve chromatogram of the same compounds as in Figure 12.1, where the injected amount is maximized in order to ophmize the process [5]. 

Figure 12.1 Analytical chromatogram of a racemic 1-azabicyclo[2.2.2]octyl derivative. Chiralcel OJ 20pm, MeOH -+- 0.1% DEA, flow rate = 1 mimin, injected amount = lOpg.

Batch processing appears as one of the simplest ways to use chromatography. This process uses one column and operates in a succession of injections (at the inlet of the column) and collections (at the outlet of the column). The eluent consumption is the ratio of the volume of eluent used divided by the amount of product purified. Reduction of the eluent consumption can be achieved by, for example, increasing the injected amount or reducing the cycle time [12]. 

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