8. Compare the advantages and limitations of column chromatography with those of thin-layer and gas chromatography. Discuss all 3 chromatography methods. When you would use them and in which case is each useful and not useful?.

You are trying to separate a sample with 2 components: X and Y with GC. X has a lower boiling point than Y. Which one has a higher retention time? What is the most common way to increase retention of analytes in gas chromatography?

Consider Table 1, which lists the volumes of the Fe3+ and SCN- solutions used for the continuous variation method. Note that each of the stock solutions is 0.002 M before mixing. What are the initial concentrations of Fe3+ and SCN- for solution 4, where the volumes are both 5 mL? [Initial meaning after they are mixed, but before]they reach equilibrium)

In the second paragraph you should define and describe the process of gas chromatography. In this paragraph answer the following questions: a) Why might it be necessary to dilute the sample? Approximately how much sample is used? b) Describe good injection technique. What sort of syringe is used in gas chromatography? c) What property of compounds will make the retention time longer or shorter? Use as an example ethyl acetate, propyl acetate, and butyl acetate, since these compounds are the ones we are studying in this experiment. d) What are a few different types of detectors and how do they work?

Explain how column chromatography and planar chromatography methods are performed.

The following statements are true for any chromatographic analysis except: The analyte component interacting most strongly with the stationary phase elute faster than those with weaker interactions. On the other hand, those with least interaction with the mobile phase elute the slowest. Interactions between mobile phase-analyte - stationary phase can be both chemical and physical in nature. Chromatography is a separation technique. Electromagnetic radiation source for XPS. Gamma ray X-ray UV-Visible Infra red Radiowave The part of SEM that is responsible for the production of electrons. * Electron guns Condenser lens Secondary detector Electron beam

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What are the general characteristics of Gas Chromatography, Thin Layer Chromatography, Ion Exchange, HPLC, SEC and Affinity Chromatography?

The fraction of sample in the stationary phase in reverse phase liquid chromatography will increase when water is added to the mobile phase. Why?

Chromatography 1. External Standard Method A. Calculate the regression equation and the R-squared value. B. Calculate the concentration of cocaine found in the blood samples of the presidentiables. Which presidential candidate “reliably” tested positive for cocaine?   2. Internal Standard Method >Calculate the concentration of party drug X in the blood samples of the presidential candidates. >Suppose the LOD for party drug X is 0.200 ppm, which of the presidential candidates “reliably” tested for party drug X?