Ch 9 Flashcards
what are two types of photometers and what do they use
filters–> photometer
prisms and grafting –> spectrophotometer
UV radiation wavelength
wave length of IR
100-400 nm –> 380 nm
about 750 nm
what demonstrates that as the concentration increases absorbance increases but transmittance decreases
Beers law
what are the performance peramaters for for photometry/spectrophotometry
what are the fxn of photo/ spectrophotometry
compare the unknown with the published determined value
to isolate and use discrete portion of spectrum form measurement
what is reflective photometry
diffused light illuminates a reaction mixture in a carrier and reflected light is measured
Dry film chemistry
what is is used for
and what technique utilizes it
used for blood, urine and spinal fluid
reflective photometry
an element in the sample is excited ad radiant energy produced is measures as the element returns to its lower level
(elements: aluminum, copper, lead, zinc. calcium and magnesium )
atomic absorption spectrophotometry
what is the flameless method of atomic absorption spectrophotometry referred to
what is fluorometry
Zeeman correction
measurement of emiited fluorescent light
what occurs when a molecule absorbs at one wavelength and emits in a longer wavelength
Difference between fluorescent and phosphoresces
what is stroke shift
fluorescence
phosphoresces is excited at a higher energy state and takes longer to excite
stroke shift is when the max wavelength of excitation light and max wavelength of emission light is constant
how does time resolved fluorescence limit background scatter
how does fluorometry correlate to beers law
what is inner filter effect
time delay between absorption, energy and fluorescence
flourencece intensity is directly proportional to the concentration of fluorphore and intensity of excitation–> only if absorbace is 2%
inner filter effect is when absorbance is greater than 2%
why in fluorometry do we use the right angle approach
what reduces the inner filter effect
what is flow cytometry
to minimize background signal
emission slit near the front edge of sample cell
measure of physical and or chemical change of cell particles
what photoflurometer is used to analyze zinc protoprophyin in whole blood’
name some limits of fluorometry
luminometry –> inc. sensitivity what does it measure
hematoflurorometer
inner filter affect, conc. quenching, background fluoresces, temp flux
emission of light by a substance that has not been heated (chem,bio,electro) ; hormones and infectious disease
name two means of measuring scattered light
what is the difference between the two
nephelometry and turbidimety
T: measures intensity of light scatter difficulties–> signal to nose ratio signal: incoming nose and noises is incident light
N: measures light energy scatted or reflected toward detector at not in direction path of transmitted light at right angle
what is photometry
spectrophotometry
measurement of luminous intensity of light –> absorbance
measurement of intensity of light at a selected wavelength –> absorbace
