The term “column bleeding” refers to: _______________.
A) leak of carrier gas from the column.
B) poor resolution of low volatility compounds.
C) stationary phase decomposition.
D) decomposition of analytes on the column.
E) stationary phase contamination.
Column bleeding results from thermal breakdown of the stationary phase at temperatures close to the upper temperature limit of the column. Hence (C) Stationary Phase Decomposition, is the correct option.
The term “column bleeding” refers to: _______________. A) leak of carrier gas from the column. B)...
As you increase the gas chromatography column temperature, analytes’ ______________ increases and stationary phase solubility _______________. A) boiling point; increases B) vapor pressure; decreases C) vapor pressure; increases D) retention time; increases E) retention time; decreases
1. Select an appropriate type of column for separating these steroids and give the rationale for your selection. HO HO ОН OH Prednisolone Prednisone 2. You are using a C18 Reverse Phase column and the parameters shown below to separate Acetaminophen, Caffeine, and Benzoic Acid. You observe three peaks in your chromatogram (Huzzah!). Which corresponds to which compound? Explain the rationale behind your assignment. OH C18 REVERSED PHASE COLUMN Acetaminophen HC N H, O Caffeine Column: Legacy L1 Size: 4.6...
PRELABORATORY ASSIGNMENT 1. Provide the key term that corresponds to each of the following definitions. (a) the study of compounds derived from plants and animals (b) a method for separating a mixture into its components as a result of a varying attraction of compounds for a mobile solvent on a stationary solid (c) the leading edge of the solvent, which travels from the bottom of the developing chamber to the upper portion of the chromatogram (d) refers to solvent that...
Put the analytes in order of increasing hydrophobicity. Which of the compounds is most hydrophilic? Which is most hydrophobic? What is the predicted elution order from a reverse phase chromatography column? a. acetophenone b. benzophenone c. butylparaben d. propiopheneone e. ethylparaben f. propylparaben g. ketoprofen h. 3-nitrophenol i. 4-nitrophenol 2. Put the analytes in order of increasing hydrophobicity. Which of the compounds is most hydrophilic? Which is most hydrophobic? What is the predicted elution order from a reverse phase chromatography...
In the C programming language and in the context of this course, a "memory leak" refers to: A. what happens when a region of local memory in a function is no longer accessible when the function returns. B. what happens when a region of a text file is no longer accessible when that file is overwritten using `fopen()`. C. what happens when code copying into a character array goes beyond the bounds of that array. D. what happens when a...
A group of analysts was working on developing a method to separate and determine carbamate insecticides used for control of pests in food production They used HPLC with an Eurospher 100-5 C-18 column and a mobile phase consisting of a mixture of water and methanol, with post-column derivatization. .The column was determined to have an average of 1999 theoretical plates for this group of compounds. The stationary and mobile phases volumes in the column were SMV = 0.51mL, V =...
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Which of the following statements holds true for the term, community wage level? a. It refers to a structure for determining salary increases that encourages work that is less effective, less efficient, or both. b. It refers to the standard range of wages paid at a location, usually across a city or a region. c. It refers to the salary range a company sets for its employees, independent of the community wage level and wages as set by other, competing...
question #2 please Reverse phase chromatography is the most common type of liquid chromatography which the solid phase is made up of a packing material that is largely hydrophobic and the eluents are of varying polarities. In general, the more polar compounds elute first from the column followed by more hydrophobic compounds. PRELAB QUESTIONS 1. Draw structures for the following analytes for the simulation: a. acetophenone b. benzophenone c. butylparaben d. propiopheneone e. ethylparaben f. propylparaben g. ketoprofen h. 3-nitrophenol...
1.Another term that refers to the average rate of return is the: A: variance. B: standard deviation. C: real return. D: mean. E: histogram. 2. The excess return is computed by ______ the average return for the investment. A: subtracting the inflation rate from B: adding the inflation rate to C: subtracting the average return on the U.S. Treasury bill from D: adding the average return on the U.S. Treasury bill to E: subtracting the average return on long-term government...