Analytical Techniques

Question 1

A tech is performing an enzyme assay at the 340 nm using a visible range spectrophotometer. After setting the wavelength and adjusting the readout to zero %T with the light path blocked, a civet with DI water is inserted. With the light path fully open and the 100% T control at a max, the instrument readout will not rise above 90% T. What is the most appropriate first course of action? (3)

Answer 1

1. change the light source
2. change the monochromator
3. clean cuvett

Question 2

a red colored solution would show highest transmittance at

Answer 2

620

Question 3

a red colored solution would show highest absorbance at

Answer 3

450

Question 4

a photomultiplier tube may be described by all of following except:
A. rapid response time
B. must be shielded from stay light
C. cannot be used with a chopper
D. amplifies current significantly.

Answer 4

C

Question 5

what does this describe: cannot be used with a chopper

Answer 5

sudder

Question 6

which type of photodetector has linear array. that allows it to respond to a specific wavelength resulting in complete UV/visible spectrum analysis

Answer 6

photodiode array

Question 7

what isolates light within a narrow region of the spectrum

Answer 7

monochromator

Question 8

what is the difference between a fluorimeter and a spectrometer

Answer 8

fluorimeter use filters to select the wavelengths of incident light. and spectrometers use monochrometers

Question 9

what is the major difference in the arrangement of major components between spectrometers and atomic absorption spectrometer