ttering technique. If the formulation of the subject sample has included surfactants or salt additives, which of the following would adequately apply? . The additives would impact the ionic strength of the sample B. The impact of additives influence can be nullified when using a Light Scattering technique. C. The effect of formulation additives would impact the protein sample analysis, and should be considered as a factor when analyzing the protein aggregation using light scattering technique.

Which of the following is not an advantage of instrumental methods? a. The ability to perform trace analysis. b. No standard is required A large numbers of samples may be analyzed very quickly. d. Most instrumental methods are multichannel techniques.

True or False.  1. The absorbance of a sample is equal to the negative logarithm of the transmittance. 2. Winkler method of dissolve oxygen determination is an example of iodometry. 3. A diazo compound is produced when nitrite is reacted with sulfanilamide in acidic solution. 4. Atomic Absorption Spectroscopy can be used to analyze the functional groups of organic substances. 5. A diode array spectrometer use an absorption or interference filters for wavelength selection and a photoelectric device for measuring radiant power. 6. The oxidation state for the manganese in the brown solid which precipitate in Winkler method is +3 7. In Winkler method, the iodine produced is oxidized during sodium thiosulfate titration to iodide ion. 8. When the pH of the solution is adjusted to pH greater than 12, the EDTA reacts with magnesium ions only, because calcium precipitates as calcium hydroxide.

What compounds present in a sample that can cause error in the analysis and alter desired results?   A. Matrix B. Selectivity C. Analyte D. Interference

A student weighed out 0.150 g of protein powder and dissolved it in 100 mL of water (Solution 1). The student then diluted this solution by transferring 1 mL into a 25 mL flask and diluting with water (Solution 2). Finally, 1 mL of that solution was transferred to a test tube and combined with 4 mL Bradford reagent. The absorbance of the solution in the test tube was 0.11. Assuming that the best fit linear line of the standard curve was y = 0.04144 x + 0.01521 (μ g mL), calculate the percent protein by mass in the original protein powder.

The term masking generally refers to: A) Masking generally refers to the transformation of an interfering species into a form that is not detected.   B) Selecting samples from which the identity has been masked. This procedure prevents the analyst from prejudging the outcome of the analysis.   C) Removing any material that may interfere with an analysis.

A takes polychromatic light and provides monochromatic light to pass on to the sample and then detector in a UV-Vis spectrophotometer. A. polychromator B. photodiode array C. monochromator D. charge couple device E. photomultiplier tube

A student weighed out 0.150 g of protein powder and dissolved it in 100 mL of water (Solution 1). The student then diluted this solution by transferring 1 mL into a 25 mL flask and diluting with water (Solution 2). Finally, 1 mL of that solution was transferred to a test tube and combined with 4 mL Bradford reagent. The absorbance of the solution in the test tube was 0.144. Assuming that the best fit linear line of the standard curve was y=0.04144x+0.01521 (μgmL), calculate the percent protein by mass in the original protein powder.

1) You are asked to prepare a buffer for a protein assay. This protein works best at a slightly acidic pH of 5.5.  a. From the list of Acids and conjugate bases which pair would you pick.  (The list is in the attached image)  b. You are asked to make a 1M stock solu on of the Buffer, how many grams of each acid and base would you need to make a 500mL stock. c. For the experiment, the final concentra on of the buffer should be 50mM. How many mL of your stock would you need to make 2L. Hint: M1V1=M2V2

Interference in sample can have following impact except a. Amount of time needed for analysis is decreased as there is less analyte. b. The analyte cannot be detected as interference reacts with analyte. c. The interference reacts with reagent used in the analysis and analyte is not detected. d. The level of the analyte is increased as the interference level is also measured.