Q: IN GC, What effect does changing from a temperature ramp to an isothermal temperature program have…
A: Gas chromatography is the process of separating compounds in a mixture by injecting a gaseous or…
Q: Which of the following would result in an increase in the calculated ngas in the Chem 16.1 Experin…
A: The correct option is as follows:
Q: What are the similarities and differences between a chromatogram from an HPLC with a diode array…
A: A chromatogram formed after chromatography technique. A chromatography is a technique to separate…
Q: 1. List three criteria that is important to consider when choosing a solvent for recrystallization…
A: Since you have asked multiple questions we will answer the first one for you. To get the remaining…
Q: Help please : When comparing HPLC with Gas Chromatography , Gas Chromatography analysis may require…
A: Chemical derivatization is a step in gas chromatography in which a compound is chemically…
Q: The height of three peaks; A, B, and C obtained in a gas chromatogram are 20.6 mm, 17.5 mm and 40.6…
A: A numerical problem based on gas chromatography, which is to be accomplished.
Q: We use reverse phase column chromatography with a non-polar C18 stationary phase and a mixture of…
A:
Q: Explain shortly how the chromatography will be influenced in a C18 reverse phase liquid…
A: “Since you have posted a question with multiple sub-parts, we will solve first three sub-parts for…
Q: What are the advantages of evaporative-light scattering detector when used with high-precision…
A: ELSDs are aerosol-based HPLC detectors which work by converting the eluents of target components…
Q: 10. Consider the following compounds when answering the questions below. Assume these compounds can…
A:
Q: What are the different technical considerations in performing the serum protein electrophoresis…
A: Answer - The serum protein electrophoresis (SPEP) test measures specific proteins in the blood to…
Q: from one of our neigboring countries are heavily contaminated with pesticides. Upon analysis, some…
A: WORKING OF SOLID PHASE MICROEXTRACTION :
Q: Would column chromatography have worked in the separation of a fluorenone and benzoic acid mixture?…
A: Yes, they can be separated. For that, add a sufficient amount of concentrated aqueous sodium…
Q: Column Chromatography) What complications would a dried-out column (solvent level is below the top…
A: column chromatography is the technique used to separate compounds of different polarity .In this…
Q: What spectroscopic technique are you going to suggest to a mining company who wishes to determine…
A: A question based on spectroscopy, which is to be accomplished.
Q: Gradient elution used in HPLC. How is the gradient created for a reverse-phase HPLC experiment over…
A: Given that Gradient elution is used in HPLC. To find: How is the gradient created for the…
Q: What kind of sample cleanup does solid-phase extraction accomplish in the analysis of caffeine and…
A: Introduction: Extraction is the process of separation of the molecules. There are two types of…
Q: Why are collision cells a necessary addition to mass spectrometers that employ electrospray…
A: In mass spectrometers that employ electrospray ionization, a major challenge is how one can fragment…
Q: Seawater was spiked with phosphate to achieve a quantifiable range of phosphate concentrations by…
A: A question based on analytical process that is to be accomplished.
Q: how would you sample, preserve and prepare these samples for GC analysis and why GC is the best…
A: By injecting a gaseous or liquid sample into a mobile phase, which is frequently referred to as the…
Q: Suggest a reason why the optimum linear flow rate is much higher in gas chromatography than in…
A: Given:- The optimum linear flow rate is much higher in gas chromatography than in liquid…
Q: tabulated
A: To get: Common characteristics, advantages, and disadvantages of below:- 1) Paper chromatography…
Q: The identity of a volatile petroleum residue is determined by the (size, pattern) of its gas…
A: The identity of a volatile petroleum residue is determined by the (size, pattern) of its gas…
Q: Which of the following factors DOES NOT affect retention time of a sample undergoing normal phase…
A: Retention time is the time period where a sample spend on column. Here we have to tell which factor…
Q: (a) Use the information given below to sketch and label a molecular exclusion calibration curve. Use…
A:
Q: Column chromatography is also very useful for separating mixtures of organic compounds that are not…
A: Column chromatography is one of the most useful methods for the separation and purification of both…
Q: Choose the best answer. What are the factors that need to be considered in HPLC to ensure the two…
A: Introduction : HPLC means High pressure liquid chromatography it is used to find out the drug…
Q: 19. What type of sample analysis usually operates on the 10-4 g scale of sample size? A. macro…
A: 19. Option D. Ultra micro analysis
Q: Which of the following factors DOES NOT affect retention time of a sample undergoing normal phase…
A:
Q: Which of the following is TRUE for a reversed phase chromatography experiment? i. Less polar…
A:
Q: Explain the difference between wall-coated, support-coated, and porous-layer open tubular columns…
A: In wall coated columns the stationary liquid phase rests on capillary column which in turn consists…
Q: Include the theory of how molecules interact with and elute from molecular stationary phase of GC GC…
A: The sample is first injected into a mobile phase present in gaseous state also called as the Carrier…
Q: What properties should the stationary-phase liquid for gas chromatography possess?
A: Desirable properties of the stationary phase for GC include low volatility, thermal stability,…
Q: Explain the following Chromatography (for drug analysis) Thin-layer chromatography (TLC) Gas…
A:
Q: 1. The properties that must be possessed by the adsorption reagent in air sampling are… a. Reagents…
A: Air sampling is the process by which the type and quantity of airborne contaminants present in an…
Q: For thin layer chromatography, why should a piece of filter paper that is moistened with the…
A: Purpose of the Filter Paper in the Thin-Layer Chromatography :- Filter paper is placed in the…
Q: Water and methanol are separated using a 1.0-m packed gas chromatography column. An unretained…
A: The linear velocity of the mobile phase is calculated with the help of equation (1) where L is the…
Q: What is the difference between a reconstructed total ion chromatogram and a selected ion…
A: Mass chromatography is a technique used to analyze the structural features for given family of…
Q: Calculate the separation factor (or selectivity factor), between two compounds, 1 and 2, whose…
A: The selectivity factor (α) of a column for two analytes A and B where A eluting before B is given…
Q: 3. Compare column, thin-layer, and gas chromatography in terms of: a. mobile phase b. stationary…
A: Here i have compared all the chromatographic techniques
Q: different laboratory with a cooler temperature. III. A shorter equilibration time prior to…
A: From ideal gas equation: We know ρv=ngas RT Where ρ=pressure v=Volume R=Universal Gas constant…
Q: The following statements are true for any chromatographic analysis except: The analyte component…
A:
Q: What is the purpose of solid-phase extraction? Why is it advantageous to use large particles (50 mm)…
A: An extraction method where compounds are suspended (or) dissolved in mixture of liquid are isolated…
Q: Explain shortly how the chromatography will be influenced in a C18 reverse phase liquid…
A: “Since you have posted a question with multiple sub-parts, we will solve first three sub-parts for…
Q: What kind of information does a mass spectrometer detector give in gas chromatography that is useful…
A: Quantitative analysis- Chemical analysis designed to determine the amounts or proportions of the…
Q: Gradient elution used in HPLC. How is the gradient created for a reverse-phase HPLC experiment over…
A: High performance liquid chromatography or HPLC is an analytical technique used to identify and…
Q: The chlorophyll sample contains Mg2 + ions. Briefly describe the sequencing steps to determine the…
A: Determination of magnesium ion using Erichrome Black-T as indicator: The concentration of Mg2+ ion…
Q: The following organic solvents were used in reversed phase HPLC analysis. Propose he elution order…
A:
Q: What is the advantage of microwave ashing and microwave digestion in sample preparation prior…
A: These both methods are the advanced methods to which the sample is subjected prior instrumental…
- Briefly explain four importance of conducting sample preparation prior to instrumental analysis.
- Consider the following situations:
- If you were to analyse traces of petroleum from a piece of burned carpet, which sample preparation method is more suitable, solid phase microextraction (SPME) or pressurized liquid extraction (PLE)? Explain the choice of method chosen and why the other method is not suitable.
- If you were to analyse caffeine in a coffee drink, which sample preparation method is more suitable, solid phase microextraction (SPME) or solid phase extraction (SPE)? Discuss the reason for your choice and the reason for not choosing the other method.
Step by step
Solved in 2 steps
- What are the advantages and disadvantages of using external standards in instrumental analysis?You are an aquatic scientist and tasked to sample water that contains chlorophenols for gas chromatographic analysis from your local waste water treatment plant (WWTP). Using knowledge of sample preparation and chromatograph, how would you sample, preserve and prepare these samples for GC analysis and why GC is the best detection technique?Can paper chromatography be used to separate and identify very volatile substances? Why? Please explain comprehensively.
- What are the differences between systematic and random errors and how do they effect accuracy and precision? In what circumstances would you use standard addition (versus a normal calibration curve) to determine the amount of an analyte in a sample? A urine sample, containing analyte Z is analysed by the standard addition method where 5 mL of the original sample was mixed with increasing amounts of a Z standard and each solution diluted to a volume of 50 mL prior to analysis. A plot of the final concentration of the standard in each of the 50 mL samples (x axis) versus The measured signal from the analysis of each 50 mL sample (on y axis) produced a straight line with the general equation: y = 44.72x + 4.06 what was the final concentration of Z in the 50 mL standard addition sample? what was the initial concentration of Z in the original urine sample?A chemist received a radioactive sample that is suspected to contain U, 23U and other elements. The authority wants to know the distribution, qualitative and quantitative composition of the sample. Propose with justifications, ONE Surface analysis technique that can be performed on this sample.Why is strict implementation of LQMS (Laboratory Quality Management System) or GLP is necessary ? What are the elements ?
- Why chromatography is an important tool for analysis of organic compounds?One method for quantitative determination of the concentration of constituents in a sample analyzed by gas chromatography is the area normalization method. In this method, complete elution of all of the sample constituents is necessary. The area of each peak is then measured and corrected for differences in detector response to the different eluates. This correction is accomplished by dividing the area by an empirically determined correction factor. The concentration of the analyte is found from the ratio of its corrected area to the total corrected area of all peaks. For a chromatogram containing three peaks, the relative areas were found to be 16.4, 45.2, and 30.2 in the order of increasing retention time. Calculate the percentage of each compound if the relative detector responses were 0.60, 0.78, and 0.88, respectivelyAs part of an analytical chemistry laboratory course, a student measured the Ca2+ content in two water samples, city-supplied drinking water and well-supplied drinking water, using two different analytical methods, flame atomic absorption spectrometry (FAAS) and EDTA complexometric titration. The results of this experiment are given in the table as the mean Ca2+concentration (?¯) and standard deviation (?) in parts per million (ppm). Each sample was measured five times (n=5) by each method. Method City-Supplied Drinking Water (?¯±?x¯±s) Well-Supplied Drinking Water (?¯±?x¯±s) FAAS 57.57±0.68 ppm 64.77±0.70 ppm EDTA titration 58.32±0.96 ppm 65.62±0.97 ppm Method Comparison: For each drinking water sample (city and well), compare the Ca2+ content measured by FAAS and EDTA titration. Calculate the ? value for each sample. Do the methods produce statistically different results at the 95% confidence level when measuring the Ca2+content of the city-supplied drinking water? Do the…
- One method for the quantitative determination of the concentration of constituents in a sample analyzed by gas chromatography is area normalization. Here, complete elution of all the sample constituents is necessary. The area of each peak is then measured and corrected for differences in detector response to the different eluates. This correction involves dividing the area by an empirically determined correction factor. The concentration of the analyte is found from the ratio of its corrected area to the total corrected area of all peaks. For a chromatogram containing three peaks, the relative areas were found to be 16.4, 45.2 and 30.2, in order of increasing retention time. Calculate the percentage of each compound if the relative detector responses were 0.60, 0.78 and 0.88, respectively.In a Bradford assay, 11 µl of a protein isolate sample was diluted by adding 21 µl of water prior to the addition 2.0 mL Bradford reagent. Calculate the protein concentration (in mg/mL) of the original protein isolate sample whose absorbance reading at 595 nm is 0.304 after dilution. The protein standard solutions used for the calibration curve of the Bradford assay was constructed using bovine serum albumin (BSA) stock solution whose concentration is 200 µg/mL. The concentration and the corresponding absorbance reading at 595 nm of the protein standard solutions are summarized in the table below: Standard soln # 1 2 13 4 6 conc of BSA 12.00 24.00 36.00 48.00 60.00 (pg/mL) Absorbance at 595 nm 0.000 0.156 0.249 0.328 0.411 0.528 zNote: Final answer format must be x.xxx (three decimal places). Round off only in the final answer. Do not round off in the middle of the calculation.In a volumetric determination of an analyte A, the data obtained and their standard deviations are as follows: Initial buret reading 0.19 mL 0.02 mL Final buret reading 7.86 mL 0.03 mL Sample mass 63.0 mg 0.2 mg From the data, find the coefficient of variation of the final result for the %A that is obtained by using the equation that follows and assuming there is no uncertainty in the equivalent mass. %A= titrant volume x equivalent mass x 100 %/ sample mass Coefficient of variation = Submit Answer % Try Another Version 10 item attempts remaining